ORCID Profile
0000-0003-3403-1465
Current Organisation
University of Florida
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Publisher: Elsevier BV
Date: 07-2004
Publisher: American Dairy Science Association
Date: 2011
Abstract: The objectives were to evaluate the effects of differential timing of supplementation of different Ca salts (CS) of fatty acids (FA) on FA profiles of cotyledonary-caruncular tissues, metabolic status, uterine health, pregnancy, pregnancy losses after 2 artificial inseminations (AI), and milk yield. Holstein cows (n=1,380) were assigned randomly to be fed either CS of palm oil (PO) or safflower oil (SO) from 30 d prepartum until 30 d postpartum (dpp) and further randomized to receive either CS of PO or fish oil (FO) from 30 to 160 dpp. Supplementation of CS of FA was at 1.5% of dietary dry matter. Tissues (n=23) and blood (n=32) were collected from a subs le of cows. Blood was collected daily from parturition to 10 dpp and three times weekly thereafter until 30 dpp for analyses of PGF2α metabolite, nonesterified FA, β-hydroxybutyric acid, blood urea nitrogen, and glucose. Cows were evaluated once between 8 to 10 dpp for cervical discharge type. At 43 dpp, cows received 2 injections of PGF2α 14 d apart, followed 14 d later by injections of GnRH at 7 d before and 56 h after an injection of PGF2α with AI at 16 h after the second GnRH injection. All cows received intravaginally a controlled internal drug-releasing device, containing 1.38 g of progesterone, at 18 d after the first AI followed 7 d later by removal of the device and injection of GnRH. Nonpregnant cows at 32 d after AI were injected with PGF2α, followed 56 h later with a GnRH injection and second AI 16 h thereafter. Cows diagnosed pregnant after both AI were re-examined at 60 d of pregnancy to determine pregnancy losses. Milk weights were recorded monthly for all cows. Caruncular n-6:n-3 FA ratio was greater in cows fed SO. Plasma concentrations of metabolites and frequency of cervical discharge type did not differ between PO- and SO-fed cows. Plasma PGF2α metabolite was greater in SO-fed cows at 4 and 7 dpp. Pregnancy per AI at 32 and 60 d post first AI was not affected by diets, but pregnancy loss was less in FO-fed cows. At second AI, pregnancy was greater in FO-fed cows at 32 d and in SO-FO-fed cows at 60 d post AI. Pregnancy loss after second AI was not affected by diets. Overall pregnancy per AI was greater in cows fed SO followed by FO at 60 d of pregnancy and pregnancy loss was reduced in FO-fed cows. Monthly milk yield was greater (0.7 kg/d) in SO-fed cows. In conclusion, strategic feeding of CS of FA during transition and breeding periods can benefit fertility and milk production of lactating dairy cows.
Publisher: American Dairy Science Association
Date: 05-2011
Abstract: The objectives were to evaluate the effects of differential supplementation of Ca salts (CS) of fatty acids (FA) on plasma acute phase proteins and both FA composition and function (i.e., activity and cytokine production) of neutrophils, during the peripartum and breeding periods. Holstein cows were assigned randomly to receive either CS of palm (PO) or safflower (SO) oils from 30 d prepartum until 35 d postpartum (dpp) and CS of PO or fish oil (FO) from 35 to 160 dpp. Supplementation of CS of FA was at 1.5% of dietary dry matter. Cows (n=32) were s led three times weekly from parturition to 35 dpp for analyses of plasma concentrations of haptoglobin and fibrinogen. Cows (n=47) were s led for neutrophil phagocytic and oxidative burst activities toward Escherichia coli and Staphylococcus aureus, and neutrophil abundances of L-selectin and β(2)-integrin assessed by flow cytometry at 32 d prepartum, within 7h after parturition, and 4 and 7 dpp. Profiles of FA in neutrophils and cytokine production (i.e., tumor necrosis factor alpha, TNF-α, and IL-1β) were assessed prepartum (n=14), 35 (PO vs. SO n=26) and 85 dpp (PO vs. FO n=28). Plasma concentrations of haptoglobin and fibrinogen were greater for cows fed SO compared with PO. The percentage of neutrophils with phagocytic and oxidative burst activities was not affected by transition diets, but activities per neutrophil were greater in SO compared with PO diets at 4 (phagocytosis and oxidative burst) and 7 dpp (oxidative burst). Neutrophil abundance of L-selectin, but not β(2)-integrin, was greater in SO compared with PO at 4 and 7 dpp. Neutrophil productions of TNF-α and IL-1β were increased at 35 dpp in SO compared with PO diets, but production of TNF-α was attenuated in FO compared with PO at 85 dpp. Neutrophil ratios of n-6:n-3 FA were greater at 35 dpp in the SO diet and less at 85 dpp in FO compared with PO diets. In conclusion, cows supplemented with CS of SO had improved innate immunity (i.e., acute phase response and neutrophil function) to better cope with the bacterial challenges in the postpartum period. Conversely, CS of FO attenuated neutrophil cytokine production.
Publisher: Bioscientifica
Date: 07-2020
DOI: 10.1530/REP-19-0564
Abstract: Infection of the postpartum uterus with pathogenic bacteria is associated with infertility months later in dairy cattle. However, it is unclear whether these bacterial infections lead to long-term changes in the reproductive tract that might help explain this infertility. Here we tested the hypothesis that infusion of pathogenic bacteria into the uterus leads to changes in the transcriptome of the reproductive tract 3 months later. We used virgin Holstein heifers to avoid potential confounding effects of periparturient problems, lactation, and negative energy balance. Animals were infused intrauterine with endometrial pathogenic bacteria Escherichia coli and Trueperella pyogenes ( n = 4) and compared with control animals ( n = 6). Three months after infusion, caruncular and intercaruncular endometrium, isthmus and ulla of the oviduct, and granulosa cells from ovarian follicles mm diameter were profiled by RNA sequencing. Bacterial infusion altered the transcriptome of all the tissues when compared with control. Most differentially expressed genes were tissue specific, with 109 differentially expressed genes unique to caruncular endometrium, 57 in intercaruncular endometrium, 65 in isthmus, 298 in ulla, and 83 in granulosa cells. Surprisingly, despite infusing bacteria into the uterus, granulosa cells had more predicted upstream regulators of differentially expressed genes than all the other tissues combined. In conclusion, there were changes in the transcriptome of the endometrium, oviduct and even granulosa cells, 3 months after intrauterine infusion of pathogenic bacteria. These findings imply that long-term changes throughout the reproductive tract could contribute to infertility after bacterial infections of the uterus.
Publisher: American Veterinary Medical Association (AVMA)
Date: 06-2003
Publisher: American Dairy Science Association
Date: 08-2014
Abstract: The objective was to evaluate the effect of supplementing saturated or unsaturated fatty acids (FA) during late gestation of cows and during the preweaning period of calves on growth, health, and immune responses of calves. During the last 8wk of pregnancy, Holstein cattle (n=96) were fed no fat supplement (control), a saturated FA (SFA) supplement enriched in C18:0, or an unsaturated FA supplement enriched in the essential FA linoleic acid. Newborn calves were fed a milk replacer (MR) with either low linoleic acid (LLA coconut oil) or high linoleic acid (HLA coconut oil and porcine lard) concentration as the sole feedstuff during the first 30d. A grain mix with minimal linoleic acid was offered between 31 and 60d of life. At 30 and 60d of life, concentrations of linoleic acid in plasma were increased in calves born from dams supplemented with essential FA compared with SFA (44.0 vs. 42.5% of total FA) and in calves consuming HLA compared with LLA MR (46.3 vs. 40.8% of total FA). Total n-3 FA concentration was increased in plasma of calves fed HLA compared with LLA MR (1.44 vs. 1.32%) primarily due to increased α-linolenic acid. Prepartum supplementation with SFA tended to improve dry matter intake (48.8 vs. 46.7kg) and improved average daily gain (0.50 vs. 0.46kg/d) by calves without affecting efficiency of gain or circulating concentrations of anabolic metabolites or hormones. Increasing mean intake of linoleic acid from approximately 4.6 to 11.0g/d during the first 60d of life increased average daily gain (0.50 vs. 0.45kg/d) without a change in dry matter intake, thus improving feed efficiency (0.63 vs. 0.59kg of gain/kg of dry matter intake). Improved weight gain in calves fed HLA MR was accompanied by increased or tendency to increase plasma concentrations of glucose (92.7 vs. 89.9g/dL) and insulin-like growth factor I (59.5 vs. 53.2g/dL), increased hematocrit (36.0 vs. 34.4%) and concentration of blood lymphocytes (4.61 vs. 4.21×10(3)/μL), lowered plasma concentrations of acid-soluble protein (78.8 vs. 91.3mg/L) and blood platelets (736 vs. 822×10(3)/μL), and increased production of IFN-γ by peripheral blood mononuclear cells at 30d of age (48.1 vs. 25.6pg/mL), possibly indicating an earlier development of the immune system. Partial replacement of coconut oil with porcine lard in MR improved calf performance and some aspects of immunity.
Publisher: American Dairy Science Association
Date: 08-2020
Publisher: American Dairy Science Association
Date: 11-2006
Publisher: Bioscientifica
Date: 05-2021
DOI: 10.1530/REP-20-0554
Abstract: Bovine granulosa cells are often exposed to energy stress, due to the energy demands of lactation, and exposed to lipopolysaccharide from postpartum bacterial infections. Granulosa cells mount innate immune responses to lipopolysaccharide, including the phosphorylation of mitogen-activated protein kinases and production of pro-inflammatory interleukins. Cellular energy depends on glycolysis, and energy stress activates intracellular AMPK (AMP-activated protein kinase), which in turn inhibits mTOR (mechanistic target of rapamycin). Here, we tested the hypothesis that manipulating glycolysis, AMPK or mTOR to mimic energy stress in bovine granulosa cells limits the inflammatory responses to lipopolysaccharide. We inhibited glycolysis, activated AMPK or inhibited mTOR in granulosa cells isolated from 4–8mm and from 8.5 mm diameter ovarian follicles, and then challenged the cells with lipopolysaccharide and measured the production of interleukins IL-1α, IL-1β, and IL-8. We found that inhibiting glycolysis with 2-deoxy- d -glucose reduced lipopolysaccharide-stimulated IL-1α 80%, IL-1β 90%, and IL-8 65% in granulosa cells from 4–8 mm and from 8.5 mm diameter ovarian follicles. Activating AMPK with AICAR also reduced lipopolysaccharide-stimulated IL-1α 60%, IL-1β 75%, and IL-8 20%, and shortened the duration of lipopolysaccharide-stimulated phosphorylation of the mitogen-activated protein kinase ERK1/2 and JNK. However, only the mTOR inhibitor Torin 1, and not rapamycin, reduced lipopolysaccharide-stimulated IL-1α and IL-1β. In conclusion, manipulating granulosa cell energy metabolism with a glycolysis inhibitor, an AMPK activator, or an mTOR inhibitor, limited inflammatory responses to lipopolysaccharide. Our findings imply that energy stress compromises ovarian follicle immune defences.
Publisher: American Dairy Science Association
Date: 05-2020
Abstract: The objectives of this study were to evaluate the effects of rumen-protected choline (RPC) supplementation from 21 d pre- to 21 d postpartum on markers of metabolic status and inflammatory response, concentrations of liposoluble vitamins, and plasma total Ca in parous Holstein cows. The hypotheses were that supplementing RPC during the transition period would reduce hepatic triacylglycerol accumulation postpartum and attenuate markers of inflammatory response following parturition, and collectively, such responses were expected to benefit health of dairy cows. Parous cows at 241 d of gestation were blocked by parity group and 305-d milk yield, and within block, they were assigned randomly to receive either 0 g/d [no choline in transition (NT), n = 55] or 12.9 g/d choline ion [choline in transition (CT), n = 58] from 21 d pre- to 21 postpartum. The RPC product was in idually top-dressed onto the total mixed ration once daily. Prepartum, treatments were supplemented (mean ± standard deviation) for the last 18.8 ± 5.7 and 19.2 ± 5.0 d of gestation in NT and CT, respectively. Supplementing RPC prepartum did not affect concentrations of plasma metabolites and inflammatory markers during the last 3 wk of gestation. Postpartum, cows fed RPC had greater hepatic concentration of hepatic triacylglycerol (NT = 3.4 vs. CT = 4.4%) and tended to have increased concentration of β-hydroxybutyrate (NT = 0.48 vs. CT = 0.53 mM) in plasma. In spite of the increased hepatic triacylglycerol in cows fed RPC, treatment did not affect the concentrations of the inflammatory marker tumor necrosis factor-α or of the positive acute phase proteins, haptoglobin and fibrinogen. Supplementing choline tended to increase the concentration of plasma triacylglycerol by 0.69 mg/dL in the first 21 d postpartum and reduced the incidence of subclinical hypocalcemia by 20.9 percentage units compared with NT. Supplementing transition cows with RPC did not affect the concentrations of liposoluble vitamins in the first 7 d postpartum or the incidence of in idual diseases or morbidity in early lactation. The inability of supplemental choline to reduce hepatic triacylglycerol might have been a consequence of the increased productive performance without additional dry matter intake.
Publisher: American Dairy Science Association
Date: 05-2020
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.THERIOGENOLOGY.2006.09.007
Abstract: The objectives of these studies were to evaluate the efficacy of a PGF(2alpha) (PGF) analog given through different routes on causing luteal regression in lactating dairy cows. In Experiment 1, lactating Holstein cows (n=118) at random stages of lactation were blocked by parity and days in milk (DIM) and, within each block, randomly assigned to receive PGF as an intra-muscular (IM) injection in the semimembranous/semitendinous muscle (CON), subcutaneous (SC) injection in the cervical area (SCN), or SC injection in the ischio-rectal fossa (IRF). Blood was s led at 0, 12, 24, 36, and 48 h after treatment for assessment of progesterone concentration. In Experiment 2, a total of 379 lactating Holstein cows, 46+/-7 DIM, were blocked by DIM and, within each block, randomly assigned to receive treatment similar to CON or IRF groups from Experiment 1. Blood was s led 0 and 48 h after treatment for assessment of progesterone concentration. Cows were classified as experiencing luteal regression when progesterone concentration was <1.0 ng/mL or <40% of initial concentration (0 h=100%). In Experiment 1, there was no effect of route of PGF treatment on decline in progesterone concentration and on the proportion of cows experiencing luteal regression by 12, 24, 36, and 48 h after treatment. Similarly, in Experiment 2, route of treatment did not affect either the decline in progesterone concentration or the proportion of cows that had luteal regression by 48 h after treatment. Treatment of lactating dairy cows with 25mg of PGF given SC in the ischio-rectal fossa did not affect either the decline in progesterone concentration or the proportion of cows that experienced luteal regression by 12, 24, 36, and 48 h after PGF treatment.
Publisher: American Dairy Science Association
Date: 06-2010
Abstract: The objectives of this study were to evaluate the effects of using sex-sorted semen for first AI of heifers on health and productivity during first lactation. Holstein heifers (herd A=227 and herd B=1,144) received first artificial insemination (AI) with sex-sorted semen (SX n=343) or conventional semen (CS n=1,028), and all heifers that displayed estrus after first AI were reinseminated with conventional semen up to 11 times before being culled. Age at first AI was 13.1+/-0.1 and 13.8+/-0.1 mo for SX and CS heifers, respectively, in herd A and 12.9+/-0.1 mo for both SX and CS heifers in herd B. Pregnancy per AI after first AI was greater for CS heifers than for SX heifers (51.8 vs. 40.2%). From heifers initially enrolled, 70.2% calved in herds A (n=188) or B (n=774) and first-lactation data were collected. Interval from first AI to calving was greater for SX heifers than for CS heifers (10.2+/-0.1 vs. 9.9+/-0.1 mo). Among heifers conceiving to first AI, SX heifers were more likely than CS heifers to deliver a female calf (85.7 vs. 47.7%), but because SX heifers were more likely to deliver a dead calf (8.8 vs. 3.4%), the difference in proportion of SX and CS heifers delivering a live female calf was smaller than expected (SX=79.1% CS=47.2%). Rearing cost from first AI to calving was greater for SX heifers than for CS heifers ($775.3+/-6.7 vs. $750.0+/-5.9), but calf revenue tended to be greater for SX heifers ($142.0+/-7.2 vs. $126.7+/-6.4) and cost per female calf produced was smaller for SX heifers than for CS heifers ($-809.4+/-10.8 vs. $-1,249.7+/-10.9). Treatment did not affect calving difficulty, proportion of heifers needing assistance, and incidence of retained fetal membranes or metritis. Among heifers that conceived to first AI, however, SX heifers were more likely to be culled within 30 DIM (3.3 vs. 1.6%) and tended to be more likely to be culled within 60 DIM (5.5 vs. 3.4%) than CS heifers, but overall replacement cost was not different ($136.8+/-13.4). Total milk yield (9,245.5+/-84.7 kg) and income over feed cost ($554.7+/-5.1) were not different. Overall economic return was greater for SX heifers than CS heifers ($-83.7+/-36.7 vs. -175.3+/-33.4). Use of sex-sorted semen for first insemination of virgin heifers reduced the cost per female calf produced and increased the economic return during the first lactation.
Publisher: American Dairy Science Association
Date: 22-06-2017
DOI: 10.3168/LDHM.0858
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.VETMIC.2017.12.022
Abstract: Broad-spectrum antibiotics such as ceftiofur and icillin are recommended for the treatment of metritis in dairy cows. Nonetheless, little is known about the impacts of antibiotics on the uterine microbiota. Here, we evaluated the shift in uterine microbiota after treating metritic cows with ceftiofur or icillin, and also gained insight into the uterine microbiota associated with cure of metritis. Uterine swabs from ceftiofur-treated, icillin-treated, and untreated metritic Holstein cows were collected on the day of metritis diagnosis (D1) and on D6 and then used for genomic DNA extraction and sequencing of the V4 hypervariable region of the 16S rRNA gene on the Illumina MiSeq platform. The uterine microbiota consolidated over time by decreasing species richness and increasing evenness therefore, becoming more homogeneous. The uterine microbial community showed distinct clustering patterns on D6 according to antibiotic treatment, which could be attributed to more dynamic changes in the microbial structure from D1 to D6 in ceftiofur-treated cows. Ceftiofur led to significant changes at the community level, phylum level, and genus level, whereas the changes in icillin and untreated cows, although following the same pattern, were mostly non-significant. Bacteroidetes was significantly increased in ceftiofur-treated cows but was not changed after icillin and no treatment. Different responses to antibiotics were observed in Porphyromonas, which increased in relative abundance with ceftiofur and decreased with icillin. Regardless of treatment group, failure to cure metritis was associated with a decrease in ersity of uterine microbiota and an increase in the relative abundance of Bacteroides, Porphyromonas, and Fusobacterium.
Publisher: American Dairy Science Association
Date: 2020
Abstract: Objectives were to determine the effects of feeding supplemental 25-hydroxyvitamin D
Publisher: Elsevier BV
Date: 2013
DOI: 10.1016/J.ANIREPROSCI.2012.10.014
Abstract: Objectives were to determine progesterone concentration (P4) from days 4 to 28 relative to presumptive estrus necessary for maintenance of pregnancy in lactating Holstein cows. Cows were assigned to the low P4 (LowP4, n=28) or control (n=153) treatments. All cows were presynchronized with two injections of PGF(2α) (14d apart) and an ovulation synchronization protocol (11d later GnRH on day -10, PGF(2α) on day -3 and GnRH on day 0=presumptive estrus). Cows in the Low P4 treatment received 2 injections of prostaglandin F(2α) on days 4 and 5 (day 0=presumptive estrus) and a new CIDR insert on day 5 that was replaced every 7d until day 28. Blood was s led on days -9, -2, 0, 4, 7,14, 21, and 28. Ovaries were examined with ultrasound on days -9, -3, and 7 and cows bearing a corpus luteum ≥20mm on day 7 received an embryo. On days 0, 4 and 7 P4 did not differ (P≥0.27) but control cows had greater (P<0.01) P4 on days 14, 21, and 28. Progesterone concentration fold change from day 0 to 7 was not (P=0.14) affected by treatment, but P4 concentration fold change from day 7 to 14 was (P<0.01) greater for control cows compared with LowP4 cows. No LowP4 cows became pregnant after embryo transfer, whereas 35.7, 25.5, and 21.4% of control cows were pregnant on day 28, 42, and 63, respectively. Progesterone concentration fold changes from day 0 to 7 (P=0.03) and from day 7 to 14 (P=0.05) were associated with pregnancy outcomes on day 63. Among cows that were pregnant on day 63, the minimum P4 concentration fold changes from day 0 to 7 and from day 7 to 14 were 2.71 and 1.48, respectively. Interestingly, cows with P4 concentration <5ng/mL on day 14 were (P=0.01) and tended to be (P=0.07) more likely to lose pregnancy from day 28 to 42 and from day 28 and 63, respectively. Faster rise in P4 concentration during the metestrus and early diestrus are associated with pregnancy establishment following embryo transfer, which suggests that early rise in P4 concentration has an indirect effect on embryo development through modulation of uterine environment and secretion of histotroph. Furthermore, the positive effects of early rise in P4 concentration appear to go beyond the phase of maternal recognition of pregnancy through adhesion and placentation stages.
Publisher: American Dairy Science Association
Date: 09-2008
Abstract: The objectives of this study were to evaluate the effects of method of presynchronization and source of supplemental Se on uterine health and reproductive performance of lactating dairy cows. Holstein cows (n = 512) were assigned randomly to 2 methods of presynchronization, Presynch (2 PGF(2a) given 14 d apart) or CIDR-PS (controlled internal drug releasing inserted for 7 d with an injection of PGF(2a) at removal) and 2 sources of Se, sodium selenite (SS) or selenized yeast (SY) supplemented at 0.3 mg/kg from 25 d before calving to 80 d in milk (DIM) arranged in a 2 x 2 factorial. Cows were inseminated following the Ovsynch protocol (d 0 GnRH, d 7 PGF(2a), d 9 GnRH, timed artificial insemination (AI) 12 h after the final GnRH) starting at 12 and 3 d after Presynch and CIDR-PS, respectively. Cows were diagnosed for pregnancy at 28, 42, and 56 d after AI. Source of Se did not influence uterine health and resumption of cyclicity, but fewer CIDR-PS than Presynch cows were cyclic at the beginning of the Ovsynch, although differences in the proportion cyclic may have been caused by the timing when corpus luteum evaluations were performed in the different pre-synchronization treatments. Ovulatory responses were not influenced by source of Se. However, the CIDR-PS increased ovulation to the first GnRH, double ovulation to the final GnRH, and size of ovulatory follicle at PGF(2a) and final GnRH of the Ovsynch, but did not influence ovulation at the final GnRH of the Ovsynch. Concentrations of estradiol during the Ovsynch increased with follicle diameter and were greater for cows receiving CIDR-PS than Presynch, but they were not influenced by source of Se. Pregnancy per AI on d 28 (32.7%), 42 (28.5%), and 56 (25.9%) after AI, and pregnancy loss (20.5%) from 28 to 56 d were not influenced by source of Se or method of presynchronization. Although cows receiving CIDR-PS had an increased incidence of ovulation to the first GnRH (73.2 vs. 57.8%) and double ovulation to the final GnRH of the Ovsynch (18.7 vs. 9.0%), both of which enhanced pregnancy, the CIDR-PS protocol did not improve pregnancy per AI or reduce pregnancy loss compared with presynchronization with PGF(2a) alone.
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.THERIOGENOLOGY.2011.02.022
Abstract: The objective was to evaluate the effect of estrus occurrence (based on removal of tail-head marks) on ovarian responses and pregnancy per AI (P/AI 30 d after AI) in suckled Bos indicus beef cows submitted to timed AI (TAI) protocols. Cows received an intravaginal device containing 1.0 g progesterone, and 2.0 mg estradiol benzoate im 8 d later, the intravaginal device was removed, and they were given PGF(2α) (0.25 mg of cloprostenol sodium) and 300 IU of eCG, with TAI 48 to 52 h later. In Experiment 1, cows were assigned to receive one of three treatments: 1 mg of estradiol cypionate (ECP) im at progesterone (P4) device removal (N = 178) 10 μg of GnRH im at TAI (N = 190) or both treatments (N = 172). In cows given estradiol (ECP or ECP + GnRH), more displayed estrus (P = 0.002) and became pregnant (P < 0.0001) compared with those receiving only GnRH. In Experiment 2, the effect of the occurrence of estrus on ovarian responses was evaluated in cows (N = 53) synchronized using ECP at device removal. Cows that displayed estrus had a greater diameter of the largest follicle (LF) at device removal (P < 0.0001), a greater diameter at TAI (P < 0.0001), a greater ovulation rate (P = 0.02), a larger CL (P = 0.02), and a greater P4 concentration (P < 0.0001) than cows that did not display estrus. In Experiment 3, the effect of GnRH treatment on P/AI at TAI was evaluated in cows that received ECP at device removal, and either displayed, or did not display, estrus (N = 726). There was no estrus by GnRH interaction (P = 0.22) the P/AI was greater (P < 0.0001) in cows that displayed estrus (61.9%) than cows that did not display estrus (41.4%). However, GnRH did not improve (P = 0.81) P/AI (GnRH = 53.7% vs. no GnRH = 52.6%). In conclusion, exogenous estradiol at device removal increased both the proportion of suckled Bos indicus cows that displayed estrus and P/AI. Cows that displayed estrus had better ovarian responses (i.e., larger follicles at TAI, a greater ovulation rate, larger CL, and greater P4 concentrations) following an estradiol/P4-based synchronization protocol. Although occurrence of estrus improved pregnancy outcomes, GnRH at TAI did not improve P/AI in suckled Bos indicus cows treated with ECP, regardless of estrus occurrence.
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.THERIOGENOLOGY.2016.04.038
Abstract: Resumption of ovulation after parturition is a coordinated process that involves recoupling of the GH/insulin-like growth factor 1 axis in the liver, increase in follicular development and steroidogenesis, and removal of negative feedback from estradiol in the hypothalamus. Infectious diseases and metabolic disorders associated with extensive negative energy balance during early lactation disrupt this pathway and delay first ovulation postpartum. Extended periods of anovulation postpartum exert long-lasting effects on fertility in dairy cows including the lack of spontaneous estrus, reduced pregnancy per artificial insemination (P/AI), and increased risk of pregnancy loss. Concentrations of progesterone in anovular cows subjected to synchronized programs for AI are insufficient to optimize follicular maturation, oocyte competence, and subsequent fertility to AI. Ovulation of first wave follicles, which develop under low concentrations of progesterone, reduces embryo quality in the first week after fertilization and P/AI in dairy cows. Although the specific mechanisms by which anovulation and low concentrations of progesterone impair oocyte quality have not been defined, studies with persistent follicles support the involvement of premature resumption of meiosis and degradation of maternal RNA. Suboptimal concentrations of progesterone before ovulation also increase the synthesis of PGF2α in response to oxytocin during the subsequent estrous cycle, which explains the greater incidence of short luteal phases after the first AI postpartum in anovular cows compared with estrous cyclic herd mates. It is suggested that increased spontaneous luteolysis early in the estrous cycle is one of the mechanisms that contributes to early embryonic losses in anovular cows. Anovulation also leads to major shifts in gene expression in elongated conceptuses during preimplantation stages of pregnancy. Transcripts involved with control of energy metabolism and DNA repair were downregulated, whereas genes linked to apoptosis and autophagy were upregulated in Day 15 conceptuses collected from anovular cows compared with estrous cyclic counterparts. Similar changes in conceptus transcriptome were not observed in estrous cyclic cows induced to ovulate follicles that grew under low and high concentrations of progesterone, indicating an effect of anovulation on embryonic development that is not mediated solely by progesterone concentrations before ovulation. Finally, risk factors for anovulation have direct effects on embryo development and uterine receptivity to pregnancy that complement those determined by insufficient concentrations of progesterone during follicular growth. One approach to minimize the impact of anovulation on fertility is supplementation with progesterone during recruitment, selection and final stages of development of the preovulatory follicle. It is suggested that a minimum of 2.0 ng/mL of progesterone is needed during growth of the preovulatory follicle to achieve P/AI similar to that of cows growing the preovulatory follicle during diestrus.
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.THERIOGENOLOGY.2016.04.037
Abstract: Loss of pregnancy can occur at many different stages of gestation and for a variety of causes but clearly produces a negative impact for reproductive and economic performances of dairy herds. This review describes four pivotal periods for pregnancy loss during the first trimester of gestation and discusses possible causes for pregnancy failure during these periods. The first period occurs during the first week after breeding with lack of fertilization and death of the early embryo producing major losses in pregnancy, particularly under specific environmental and hormonal conditions. In general, 20%-50% of high-producing lactating dairy cows have already experienced pregnancy loss during the first week of gestation with methods to decrease pregnancy loss during this period targeting improved oocyte quality by alleviating heat stress, inflammatory diseases, and body condition loss, and by increasing progesterone concentrations during preovulatory follicle development. The second pivotal period, from Days 8 to 27, encompasses embryo elongation and the classical "maternal recognition of pregnancy" period with losses averaging ∼30% but with surprising variation between farms (25%-41%). Maintenance of the CL of pregnancy is produced by the embryonic signal interferon-tau and alteration in uterine secretory patterns of prostaglandins F2α, E1, and E2. Failures or delays in trophoblast elongation and/or embryonic development result in loss of pregnancy during the second pivotal period possibly due to suboptimal histotroph. The third pivotal period is during the second month of pregnancy, Days 28 to 60, with losses of ∼12% based on a summary of published results from more than 20,000 pregnancies in high-producing dairy cows. Delays or defects in development of the chorioallantoic placentomes or embryo result in CL regression or embryo death during this pivotal period. Finally, a fourth period during the third month of pregnancy has reduced pregnancy losses (∼2%), compared with the first three periods but can be elevated in some cows, particularly in those carrying twins in the same uterine horn. Thus, there are varied causes for pregnancy losses during each pivotal period that correspond to key physiological changes in the embryo, uterine environment, and ovary. Similarly, strategies to reduce these losses are likely to require a multifaceted approach using rational methods that target the critical physiology in each pivotal period.
Publisher: American Dairy Science Association
Date: 03-2019
Publisher: American Dairy Science Association
Date: 03-2018
Abstract: The objectives of this experiment were to evaluate the effects of feeding diets with 2 dietary cation-anion difference (DCAD) levels and supplemented with either cholecalciferol (CH) or calcidiol (CA) during late gestation on lactation performance and energetic metabolism in dairy cows. The hypothesis was that combining a prepartum acidogenic diet with calcidiol supplementation would benefit peripartum Ca metabolism and, thus, improve energy metabolism and lactation performance compared with cows fed an alkalogenic diet or cholecalciferol. Holstein cows at 252 d of gestation were blocked by parity (28 nulliparous and 51 parous cows) and milk yield within parous cows, and randomly assigned to 1 of 4 treatments arranged as a 2 × 2 factorial, with 2 levels of DCAD (positive, +130, and negative, -130 mEq/kg) and 2 sources of vitamin D, CH or CA, fed at 3 mg per 11 kg of diet dry matter (DM). The resulting treatment combinations were positive DCAD with CH (PCH), positive DCAD with CA (PCA), negative DCAD with CH (NCH), or negative DCAD with CA (NCA), which were fed for the last 21 d of gestation. After calving, cows were fed the same lactation diet. Body weight and body condition were evaluated prepartum and for the first 49 d postpartum. Blood was s led thrice weekly prepartum, and on d 0, 1, 2, 3, and every 3 d thereafter until 30 d postpartum for quantification of hormones and metabolites. Lactation performance was evaluated for the first 49 d postpartum. Feeding a diet with negative DCAD reduced DM intake in parous cows by 2.1 kg/d, but no effect was observed in nulliparous cows. The negative DCAD reduced concentrations of glucose (positive = 4.05 vs. negative = 3.95 mM), insulin (positive = 0.57 vs. negative = 0.45 ng/mL), and insulin-like growth factor-1 (positive = 110 vs. negative = 95 ng/mL) prepartum. Treatments did not affect DM intake postpartum, but CA-supplemented cows tended to produce more colostrum (PCH = 5.86, PCA = 7.68 NCH = 6.21, NCA = 7.96 ± 1.06 kg) and produced more fat-corrected milk (PCH = 37.0, PCA = 40.1 NCH = 37.5, NCA = 41.9 ± 1.8 kg) and milk components compared with CH-supplemented cows. Feeding the negative DCAD numerically increased yield of fat-corrected milk by 1.0 kg/d in both nulliparous and 1.4 kg/d in parous cows. Minor differences were observed in postpartum concentrations of hormones and metabolites linked to energy metabolism among treatments. Results from this experiment indicate that replacing CH with CA supplemented at 3 mg/d during the prepartum period improved postpartum lactation performance in dairy cows.
Publisher: American Dairy Science Association
Date: 09-2007
Abstract: The objectives of this study were to evaluate the effect of 3 methods of resynchronization of estrus and ovulation for lactating dairy cows of unknown pregnancy status on conception rate and time to pregnancy. Holstein cows (n = 495) were randomly assigned to 1 of 3 treatments: 1) control (n = 167), resynchronization with a timed AI protocol upon diagnosis of nonpregnancy on d 31 after preenrollment AI (PAI) 2) CIDR-G (n = 159), use of an intravaginal progesterone insert from d 14 to 21 after AI, with AI at estrus from d 21 to 24 and initiation of a timed AI protocol on d 24 after AI in cows not reinseminated 3) CIDR-G + ECP (n = 169), the same treatment as CIDR-G but with an injection of 1 mg of estradiol cypionate at the time of progesterone insert removal. Cows were continuously reenrolled in the same treatment until diagnosed as pregnant, which resulted in a total of 1,148 AI (495 PAI and 653 resynchronized AI RAI). Blood was collected from 1,001 cows on d 14, 21, and 24 after each AI for analysis of progesterone, and ovaries were scanned on d 21, 24, and 31 after AI. The presence of an active corpus luteum was presumed based on progesterone > or = 1 ng/mL. Pregnancy was diagnosed by ultrasonography on d 31 and 61 after AI. The presence of an active corpus luteum and the incidence of luteolysis were similar for all treatments from d 14 to 24 however, luteolysis increased in the CIDR-G + ECP treatment from d 21 to 24. Conception rates for the PAI and all AI were similar on d 31 and 61 after insemination. Conception rates at 31 and 61 d after the RAI were also similar among treatments. Overall pregnancy loss for the PAI, RAI, and all AI were similar for all treatments. The accuracy of estrous detection, based on progesterone concentration within 2 d of detection of estrus, was similar for all treatments for the RAI and averaged 95.3%. The estrus-detection rate (EDR) decreased for the CIDR-G and CIDR-G + ECP treatments from d 14 to 21, but increased from d 21 to 24 compared with control cows however, the EDR was smaller for cows in the CIDR-G treatment during the entire resynchronization period compared with those in the CIDR-G + ECP and control groups. The reinsemination interval was reduced in cows receiving the CIDR-G + ECP treatment compared with control cows because of increased EDR after removal of the intravaginal insert however, the interval from study enrollment to pregnancy was not different among treatments. These results indicate that the reproductive performance of dairy cows did not differ among the 3 resynchronization treatments evaluated.
Publisher: American Dairy Science Association
Date: 03-2018
Abstract: Pregnant Holstein cows, 28 nulliparous and 51 parous, were blocked by parity and milk yield and randomly allocated to receive diets that differed in dietary cation-anion difference (DCAD), +130 or -130 mEq/kg, and supplemented with either calcidiol or cholecalciferol at 3 mg/11 kg of dry matter from 255 d of gestation until parturition. Blood was s led thrice weekly prepartum, and on d 0, 1, 2, 3, 6, 9, 12, 15, 18, 21, 24, 27, and 30 postpartum to evaluate effects of the diets on vitamin D, mineral and bone metabolism, and acid-base status. Blood pH and concentrations of minerals, vitamin D metabolites, and bone-related hormones were determined, as were mineral concentrations and losses in urine and colostrum. Supplementing with calcidiol increased plasma concentrations of 25-hydroxyvitamin D
Publisher: American Dairy Science Association
Date: 07-2018
Abstract: Bone-derived hormones play an important role in metabolism. This study examined the hypothesis that interactions between bone and energy metabolism, particularly those involving osteocalcin, are present in dairy cattle and have feedback mechanisms over time. Associations between metabolites in blood were examined in 32 Holstein cows blocked by parity and milk yield and randomly allocated to diets containing either 0.27 mg/kg dry matter (DM) calcidiol or cholecalciferol for an anticipated intake of 3 mg/d (120,000 IU/d) at 11 kg of DM, and positive (+130 mEq/kg DM) or negative (-130 mEq/kg DM) dietary cation-anion difference (DCAD) from 252 d of gestation to calving. Blood was s led every 3 d, from 9 d prepartum to 30 d postpartum, and plasma concentrations of vitamin D
Publisher: American Dairy Science Association
Date: 07-2008
Abstract: The objectives were to evaluate the associations among single nucleotide polymorphisms (SNP) in the R4C locus in exon 2 of the leptin gene and the lactational performance and health of Holstein cows. Eight hundred and fourteen lactating dairy cows had their DNA sequenced in exon 2 of the leptin gene to determine the presence of SNP in the R4C locus. Cows were milked 3 times daily, and yields of milk and milk components were recorded monthly in idually during the first 305 d of lactation. Cows were examined daily by herd personnel for diagnosis of health events such as retained fetal membranes, displacement of abomasum, lameness, and mastitis. Resulting genotypes were CC (34.6%), CT (48.2%), and TT (17.2%). Cows bearing the CT genotype had lower body condition (2.98 +/- 0.02) during the first 62 d in milk (DIM) than cows homozygous for the C (3.02 +/- 0.02) and T (3.04 +/- 0.03) alleles. Leptin genotype was associated with yields of milk and milk components, and cows homozygous for the C allele were less productive than those carrying the CT and TT genotypes. The 305-d yields of 3.5% fat-corrected milk, milk fat, and milk true protein were less in CC compared with CT cows by 258, 12, and 10.7 kg, respectively. Cows carrying the TT genotype had increased incidence of displacement of abomasum (4.3%), but genotype did not affect the incidence of retained fetal membranes, clinical and subclinical mastitis, or lameness. Risk of developing at least one clinical health disorder was influenced by leptin genotype, and cows carrying the CT genotype had the lowest risk for developing any disease (19.6%). Mating decisions to increase the frequency of cows heterozygous in the R4C locus may improve productivity and health.
Publisher: American Dairy Science Association
Date: 03-2018
Abstract: The objectives of the experiment were to evaluate the effects of feeding diets with distinct dietary cation-anion difference (DCAD) levels and supplemented with 2 sources of vitamin D during the prepartum transition period on postpartum health and reproduction in dairy cows. The hypotheses were that feeding acidogenic diets prepartum would reduce the risk of hypocalcemia and other diseases, and the benefits of a negative DCAD treatment on health would be potentiated by supplementing calcidiol compared with cholecalciferol. Cows at 252 d of gestation were blocked by parity (28 nulliparous and 52 parous cows) and milk yield within parous cows, and randomly assigned to 1 of 4 treatments arranged as a 2 × 2 factorial, with 2 levels of DCAD, positive (+130 mEq/kg) or negative (-130 mEq/kg), and 2 sources of vitamin D, cholecalciferol or calcidiol, fed at 3 mg for each 11 kg of diet dry matter. The resulting treatment combinations were positive DCAD with cholecalciferol (PCH), positive DCAD with calcidiol (PCA), negative DCAD with cholecalciferol (NCH), and negative DCAD with calcidiol (NCA), which were fed from 252 d of gestation to calving. After calving, cows were fed the same lactation diet supplemented with cholecalciferol at 0.70 mg for every 20 kg of dry matter. Blood was s led 7 d before parturition, and at 2 and 7 d postpartum to evaluate cell counts and measures of neutrophil function. Postpartum clinical and subclinical diseases and reproductive responses were evaluated. Feeding a diet with negative DCAD eliminated clinical hypocalcemia (23.1 vs. 0%) and drastically reduced the incidence and daily risk of subclinical hypocalcemia, and these effects were observed in the first 48 to 72 h after calving. The diet with negative DCAD tended to improve the intensity of oxidative burst activity of neutrophils in all cows prepartum and increased the intensity of phagocytosis in parous cows prepartum and the proportion of neutrophils with killing activity in parous cows postpartum (58.5 vs. 67.6%). Feeding calcidiol improved the proportion of neutrophils with oxidative burst activity (60.0 vs. 68.7%), reduced the incidences of retained placenta (30.8 vs. 2.5%) and metritis (46.2 vs. 23.1%), and reduced the proportion of cows with multiple diseases in early lactation. Combining the negative DCAD diet with calcidiol reduced morbidity by at least 60% compared with any of the other treatments. Cows with morbidity had lower blood ionized Ca and serum total Ca concentrations than healthy cows. Treatments did not affect the daily risk of hyperketonemia in the first 30 d of lactation. Despite the changes in cow health, manipulating the prepartum DCAD did not influence reproduction, but feeding calcidiol tended to increase the rate of pregnancy by 55%, which reduced the median days open by 19. In conclusion, feeding prepartum cows with a diet containing a negative DCAD combined with 3 mg of calcidiol benefited health in early lactation.
Publisher: Frontiers Media SA
Date: 11-2022
DOI: 10.3389/FGENE.2022.1017490
Abstract: The impact of genomic epistasis effects on the accuracy of predicting the phenotypic values of residual feed intake (RFI) in U.S. Holstein cows was evaluated using 6215 Holstein cows and 78,964 SNPs. Two SNP models and seven epistasis models were initially evaluated. Heritability estimates and the accuracy of predicting the RFI phenotypic values from 10-fold cross-validation studies identified the model with SNP additive effects and additive × additive (A×A) epistasis effects (A + A×A model) to be the best prediction model. Under the A + A×A model, additive heritability was 0.141, and A×A heritability was 0.263 that consisted of 0.260 inter-chromosome A×A heritability and 0.003 intra-chromosome A×A heritability, showing that inter-chromosome A×A effects were responsible for the accuracy increases due to A×A. Under the SNP additive model (A-only model), the additive heritability was 0.171. In the 10 validation populations, the average accuracy for predicting the RFI phenotypic values was 0.246 (with range 0.197–0.333) under A + A×A model and was 0.231 (with range of 0.188–0.319) under the A-only model. The average increase in the accuracy of predicting the RFI phenotypic values by the A + A×A model over the A-only model was 6.49% (with range of 3.02–14.29%). Results in this study showed A×A epistasis effects had a positive impact on the accuracy of predicting the RFI phenotypic values when combined with additive effects in the prediction model.
Publisher: American Dairy Science Association
Date: 2002
Publisher: Elsevier BV
Date: 04-2009
Publisher: Elsevier BV
Date: 12-2006
Publisher: American Dairy Science Association
Date: 06-2023
Publisher: American Dairy Science Association
Date: 11-2020
Publisher: Wiley
Date: 07-2008
Publisher: American Dairy Science Association
Date: 12-2022
Abstract: The objectives were to investigate whether supplementation with rumen-protected choline (RPC) during late pregnancy in Holstein cows affects offspring immunity and growth, and whether effects are utero-placental, colostrum dependent, or both. A total of 105 multiparous Holstein cows were assigned randomly to a prepartum diet (1.54 Mcal of NE
Publisher: American Dairy Science Association
Date: 22-06-2017
DOI: 10.3168/LDHM.0959
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.THERIOGENOLOGY.2014.03.018
Abstract: The present study investigated the effect of Holstein donor category (cows vs. heifers) and climate variation (hot vs. cooler season) on the efficiency of in vivo embryo production programs as well as embryo survival after transferred to Holstein recipient cows. A total of 1562 multiple ovulation (MO) procedures (cows: n = 609, and heifers: n = 953) and 4076 embryo transfers (ETs) performed in two dairy herds were evaluated. Donor cows had greater number of CLs (10.6 ± 0.6 vs. 7.5 ± 0.4 P < 0.0001) and ova/embryos recovered (7.6 ± 0.6 vs. 4.6 ± 0.4 P < 0.0001) compared with donor heifers. However, fertilization rate (47.9 vs. 82.4% P < 0.0001) and proportion of transferable embryos (31.5 vs. 67.4% P < 0.0001) were lower in donor cows than heifers, respectively. Regardless of donor category, the proportion of freezable embryos was less (P < 0.001) during hot season than in cooler season (21.4 vs. 32.8%). However, greater decline in the proportion of freezable embryos during the hot season was observed in cows (21.7 vs. 10.7%) compared with heifers (46.2 vs. 38.1% P = 0.01). In contrast, the season on which the embryo was produced (hot or cool) did not affect pregnancy rate on Day 31 (30.5 vs. 31.7% P = 0.45) and 45 (25.3 vs. 25.1% P = 0.64) of pregnancy. Regardless of the season in which the embryos were produced, embryonic survival after transferring embryos retrieved from donor cows was greater on Days 31 (36.0 vs. 30.7% P = 0.001) and 45 (28.3 vs. 23.1% P = 0.001) of pregnancy when compared with embryos from donor heifers. In conclusion, MO embryo production efficiency decreased during the hot seasons both in cows and heifers however, the decline was more pronounced in donor cows. Regardless of the embryo source, similar pregnancy rate was observed in the recipient that received embryos produced during the hot and cooler seasons. Curiously, embryos originating from donor cows had higher embryonic survival when transferred to recipient cows than embryos originating from heifers.
Publisher: Wiley
Date: 20-01-2010
DOI: 10.1111/J.1439-0531.2008.01237.X
Abstract: Objectives were to evaluate effects of feeding a calcium salt rich in linoleic and trans-octadecenoic acids (LTFA) on synthesis of prostaglandin F(2alpha) based on its metabolite (PGFM), uterine involution and pregnancy rates in lactating dairy cows. Five hundred and eleven Holstein cows were blocked according to parity, body condition score and milk yield in the previous lactation. Primiparous and multiparous cows were randomly assigned to one of the two treatments consisting of calcium salt (2% diet dry matter) of either palm oil (PO) or LTFA from 25 days prepartum to 80 days of lactation. Cows were time-inseminated at 70 +/- 3 days postpartum. Feeding LTFA tended (p = 0.08) to decrease the incidence of puerperal metritis (15.1% vs 8.8%). Primiparous cows supplemented with LTFA showed larger increase in plasma PGFM concentration at day 1 postpartum (17018 vs 6897 pm). Pregnancy rate after first insemination tended (p = 0.07) to be greater at 27 days after insemination (37.9% vs 28.6%), and was greater (p = 0.05) at 41 days after insemination (35.5% vs 25.8%) for cows fed LTFA compared with PO. These results indicate that unsaturated fatty acids fed in a rumen inert form have the potential to modulate reproductive events and improve pregnancy rates in lactating dairy cows.
Publisher: American Dairy Science Association
Date: 02-2021
Publisher: American Dairy Science Association
Date: 04-2012
Abstract: Objectives were to determine the effect of progesterone (P4) concentration on fertility of lactating dairy cows induced to ovulate follicles of the first follicular wave. Lactating dairy cows (n=989) at 38±3d postpartum were balanced by parity and body condition score and randomly assigned to 3 treatments: first follicular wave (FFW), first follicular wave with exogenous P4 (FFWP), or second follicular wave (SFW). All cows had their estrous cycle presynchronized with 2 injections of prostaglandin (PG) F(2α) given 14 d apart. Cows in the FFW and FFWP treatments started the ovulation synchronization protocol 3 d after the last PGF(2α) of the presynchronization protocol, whereas SFW cows received a GnRH injection (100 μg of gonadorelin diacetate Cystorelin, Merial Ltd., Duluth, GA) 3 d after the last PGF(2α) of the presynchronization protocol and started the synchronization protocol 7 d later. The synchronization protocol consisted of GnRH on d -10, PGF(2α) on d -3, and GnRH concurrent with timed artificial insemination (AI) on d 0. Cows in the FFWP treatment received 2 controlled internal drug release inserts containing 1.38 g of P4 from d -8 to -3. Progesterone concentration was determined on d -10, -8, -6, -3, and 0 from all cows and at 7, 14, and 21 d after AI from a subs le of cows (n=170). Cows (n=715) had their ovaries scanned by ultrasound on d -10, -3, and 7 d. Pregnancy was diagnosed at 38 and 66 d after AI. Concentration of P4 from study d -8 to -3 was lowest for FFW cows (1.4±0.1 ng/mL) and similar between SFW (3.7±0.2 ng/mL) and FFWP (3.7±0.1 ng/mL) cows. Diameter of the dominant follicle on study d -3 was greater for FFW cows (16.5±0.3 mm) than for SFW cows (15.4±0.3 mm), but diameter of the dominant follicle of FFWP cows was not different (15.9±0.3 mm) compared with that of SFW and FFW cows. The incidence of multiple ovulation was largest for FFW cows (SFW=19.5, FFW=33.6, FFWP=19.0%), but pregnancy per AI (P/AI) at 66 d was smallest for FFW cows (SFW=38.9, FFW=22.3, FFWP=32.0%). Anovular cows in the SFW (19.4 vs. 42.8%) and FFWP (22.1 vs. 37.2%) treatments had reduced P/AI compared with cyclic cows, despite having similar or greater P4 concentration from study d -8 to -3, respectively. Estrus and ovulation synchronization protocols for lactating dairy cows must result in growth of ovulatory follicle under P4 concentration >2 ng/mL to ensure high P/AI.
Publisher: American Dairy Science Association
Date: 06-2018
Abstract: This meta-analysis of 39 experiments containing 118 treatments explored the effects of diet interventions in early lactation on the proportion of dairy cows pregnant to artificial insemination (AI pregnancy to AI) and on calving to pregnancy interval. It also identified factors that may explain variation in these responses. The objectives were to identify effects of diet on reproduction, rather than differences between specific dietary interventions. The examination of calving to pregnancy interval used the more traditional method of analyzing differences between a treatment and the reference treatment used for comparison within a given experiment. The systematic review identified fewer experiments (n = 39) than had been expected. Four different multivariable models including the random effect of experiment were used to examine the effects of CPM-Dairy (version 3.08) estimated diet and production variables on proportion pregnant to AI. These models examined (1) output of products, (2) balance or duodenal availability of nutrients, (3) intake of nutrients, or (4) percentage of nutrients in the diet. The multivariable models identified positive associations between estimated increased fatty acid intake [incidence rate ratio (IRR) = 1.0003 ± 0.0001g/d ±standard error], starch intake (IRR = 1.061 ± 0.029 kg/d), metabolizable energy balance (IRR = 1.004 ± 0.002 MJ/d), and duodenal C14:0 (IRR = 1.008 ± 0.004 g/d) availability with the proportion of cows pregnant to AI, whereas rapidly fermentable sugar intake (IRR = 0.813 ± 0.054 kg/d), percentage of sugar in the diet (IRR = 0.960 ± 0.015%), and milk protein yield (IRR 0.922 ± 0.022 g/100 g per day) were associated with a reduced proportion of cows pregnant to AI. There was no multivariable model developed to assess variables associated with calving to pregnancy interval but, univariably, increased metabolizable energy balance was associated with a shorter calving to pregnancy interval whereas increased milk production was associated with longer time to pregnancy. Increased intake of some AA, particularly threonine and lysine, were associated with a longer calving to pregnancy interval. It is clear nutritional management around calving can influence reproductive success. The importance of dietary fats and increased energy and protein balances in early lactation for improved fertility outcomes is supported and suggests that starch and sugars may have different effects on the proportion of cows that are pregnant to AI. This work also highlighted a need for further focused field studies exploring the roles of specific fatty acids, AA, phosphorus, and carbohydrates on reproduction.
Publisher: Wiley
Date: 07-01-2020
DOI: 10.1111/AGE.12892
Publisher: Elsevier BV
Date: 2014
Publisher: American Dairy Science Association
Date: 02-2008
Abstract: Our objectives were to measure net fluxes of free AA (FAA) and peptide-bound AA (PBAA) across portal-drained viscera, liver, splanchnic tissues, and mammary tissues, and milk AA output of lactating Holstein cows (n = 8, 86 +/- 8 d in milk). Cows were fed an alfalfa-based total mixed ration containing 40% steam-flaked (SFS) or dry-rolled (DRS) sorghum grain. The total mixed rations were offered at 12-h intervals in a crossover design. Blood s les were obtained from indwelling catheters in portal, hepatic, and mammary veins and from mesenteric or costoabdominal arteries every 2 h from each cow and diet. Intake of dry matter was 17.9 and 18.6 kg/d of the SFS and DRS diets, respectively, but dropped to 16.3 kg/d for cows fed the SFS diet in the last 3 experimental days, s ling day included. Milk and milk crude protein yields (kg/12-h s ling) were 13.85 vs. 13.25 and 0.425 vs. 0.396 for cows fed SFS or DRS, respectively, and were not affected by the considerable drop in dry matter intake of cows fed the SFS diet during the last 3 experimental days. The portal-drained visceral flux of total essential FAA was 417 and 442 g/12 h (SEM 63) in cows fed SFS and DRS, respectively. However, the portal-drained visceral flux of 7 essential PBAA out of the 9 determined was numerically greater in cows fed the SFS diet, and total essential PBAA in that treatment was 77.4 +/- 22.2 compared with 35.4 +/- 50.2 g/12 h for cows fed the DRS diet. This phenomenon was again observed in a greater total splanchnic flux (FAA + PBAA) of 462 and 371 g/12 h in SFS- and DRS-fed cows, respectively. Mammary uptake of essential AA from both pools (free and peptide bound), and recovery of essential AA in milk, was again numerically higher in SFS-fed cows. In addition to FAA, quantifying the contribution of PBAA may improve our understanding of tissue use of AA substrates, and this may ultimately lead to improved diet formulations with respect to intestinal absorption and mammary uptake of AA.
Publisher: American Dairy Science Association
Date: 12-2019
Abstract: Two retrospective studies examining data of 7,500 lactating cows from a single herd were performed with the objective of evaluating the long-term effects of clinical disease during the early postpartum period on milk production, reproduction, and culling of dairy cows through 305 days in milk (DIM). In the first study, data regarding health, milk production, reproduction, and culling of 5,085 cows were summarized. Cows were classified according to incidence of clinical problem (metritis, mastitis, lameness, digestive problem, or respiratory problem) during the first 21 DIM (ClinD21). During 305 d of lactation, cows that had ClinD21 produced, on average, 410 kg less milk, 17 kg less fat, and 12 kg less protein compared with cows that did not have ClinD21 (NoClinD21). Although the interval to first breeding was not different between groups of interest, pregnancy rate through 305 DIM was lower in cows that had ClinD21 [adjusted hazard ratio (AHR) = 0.81]. When in idual breedings were analyzed, cows that had ClinD21 presented lower rates of pregnancy per breeding for breedings performed before 150 DIM, reduced numbers of calving per breeding for breedings performed before 200 DIM, and greater number of pregnancy losses for all breedings performed through 305 DIM. The rate of culling from calving through 305 DIM was higher in cows that had a single ClinD21 (AHR = 1.79) and in cows that had multiple ClinD21 (AHR = 3.06), which resulted in a greater proportion of cows leaving the herd by 305 DIM (NoClinD21 = 22.6% single ClinD21 = 35.7% multiple ClinD21 = 53.8%). In the second study, data regarding postpartum health and 305-d yields of milk, fat, and protein were collected from 2,415 primiparous cows that had genomic testing information. Genomic estimated breeding values (EBV) were used to predict 305-d yields of milk, fat, and protein. Genomic EBV and predicted yields of milk, fat, and protein did not differ between cows that had ClinD21 and those that did not have ClinD21. In contrast, the observed 305-d yields of milk, fat, and protein were reduced by 345, 10, and 10 kg, respectively, in cows that had ClinD21 compared with cows that did not have ClinD21. We conclude that clinical disease diagnosed and treated during the first 21 DIM has long-term effects on lactation performance, reproduction, and culling of dairy cows, which contribute to detrimental consequences of health problems on sustainability of dairy herds. Replication of our studies in multiple herds will be important to confirm our findings in a larger population.
Publisher: American Dairy Science Association
Date: 2023
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.THERIOGENOLOGY.2009.12.012
Abstract: Two experiments were conducted to test the hypothesis that the 5 d Co-Synch + CIDR (Controlled Internal Drug Release insert containing progesterone) protocol could be applied as an efficient timed AI (TAI) protocol in dairy heifers, and that treatment with flunixin meglumine (FM) during the period of CL maintenance would increase pregnancy per TAI (P/TAI) and late survival of embryos. Objectives were: 1) in Experiment 1, to compare P/TAI with the 5 d Co-Synch+CIDR protocol to a PGF(2alpha)/GnRH protocol and 2) in Experiment 2, to determine if FM administered 15.5 and 16 d after first TAI would increase P/TAI, using the 5 d Co-Synch+CIDR protocol with a new or previously used (5 d) CIDR insert. In Experiment 1, 248 heifers were assigned randomly to either the PGF(2alpha)/GnRH protocol (n=120) or the 5 d Co-Synch+CIDR protocol (n=128). Pregnancy per TAI did not differ between the 5 d Co-Synch+CIDR protocol (53.1%) and the PGF(2alpha)/GnRH protocol (45.8% P=0.22). In Experiment 2, 325 heifers synchronized with the 5 d Co-Synch+CIDR protocol were assigned randomly to receive two injections of FM (FM group n=158) at 15.5 and 16 d after TAI, or to remain as untreated controls (n=165). Pregnancy per TAI in Experiment 2 was 59.4 and 59.5% at 45 d for control and FM groups, respectively, with no differences between groups (P=0.83). The 5 d Co-Synch+CIDR protocol resulted in an acceptable P/TAI in dairy heifers. However, FM did not improve P/TAI in dairy heifers.
Publisher: Public Library of Science (PLoS)
Date: 05-10-2023
Publisher: American Dairy Science Association
Date: 11-2004
Publisher: Elsevier BV
Date: 12-2005
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/RD11916
Abstract: Reproduction is critical for the success of both dairy and beef cattle production. Inadequate reproduction impairs profitability by compromising production, delaying genetic progress and increasing expenses. A major impediment to the use of artificial insemination (AI) is the ability to detect oestrus for optimum timing of breeding. However, increased understanding of the bovine oestrous cycle has led to the development of reproductive programmes that allow precise synchrony of follicle development, luteal regression and ovulation. The advent of timed-AI protocols revolutionised reproductive management in dairy and beef herds. It allows for AI at a more desired time post partum despite oestrous cyclicity. It also allows for pre-determined re-insemination of cows diagnosed as not pregnant. In subfertile cows, such as the post partum, anoestrous beef cow and the high-producing dairy cow, strategic hormone supplementation has been used to overcome hormone deficiencies and improve pregnancy rates. Several physiological windows have been identified to optimise fertility in synchronisation programmes and they include, but are not limited to, follicle turnover, synchrony of follicular development, length of dominance, progesterone concentrations during development of the ovulatory follicle, luteal regression, peri-ovulatory steroid concentrations, length of pro-oestrus, synchrony of ovulation and AI, and progesterone rise after ovulation.
Publisher: Editora Scienza
Date: 22-11-2019
Publisher: EDP Sciences
Date: 07-2005
DOI: 10.1051/RND:2005040
Publisher: American Dairy Science Association
Date: 2023
Abstract: Data were obtained from studies in Australia, Canada, and the United States using in idual cow data from 28,230 Holstein cows to evaluate associations between parity and disease. Our goal was to develop understanding of disease risks for cows of differing parity. We hypothesized that there would be increased risks of disease and changes in metabolite concentrations with increased parity. Parity ≥5 represented 2,533 cows or 9.0%, parity 4 was 9.8% (2,778), parity 3 as 19.0% (5,355), parity 2 as 28.1% (7,925), and parity 1 was 34.1% (9,639) of the s le. Of these cows, 15.5% were in Australia, 14.7% in Canada, and 69.8% in the United States. Lactational incidence (LI) risk of clinical hypocalcemia increased with parity from 0.1% for parity 1 to 13% for parity ≥5 cows. The marked increase suggests profound differences in metabolism with increased parity. The LI of clinical mastitis was 17.4%. The odds of mastitis increased with parity to 2.5 times greater in parity ≥5 than in parity 1. The LI of lameness increased with parity specifically, the odds of lameness was 5.6 times greater for parity ≥5 than parity 1. Dystocia incidence was 8.7% and greatest for parity 1 cows. The LI of retained placenta was 7.4% and increased with parity, with the odds for parity ≥5 2.3 times greater than for parity 1. The LI of metritis was 10% and of endometritis 14%, with the greatest odds in parity 1. The LI of clinical ketosis was 3.3% with a marked increase in odds with parity. The prevalence of subclinical ketosis was 26.8% with only cows in parity 1 having lower odds than other parities. Parity ≥5 cows had greater odds (odds ratio = 1.7) of respiratory disease than parity 1 cows, which were lesser than other parities. Metabolite concentrations were evaluated in 5,154 Holstein cows in the precalving, calving, and immediate postcalving data sets. Metabolic measures near peak lactation provided 1,906 observations. Concentrations of β-hydroxybutyrate (BHB) and nonesterified fatty acids increased with parity on d 1 to 3 of lactation and at peak lactation. On d 1 to 3 after calving differences in glucose, nonesterified fatty acids, and BHB indicated a greater reliance on mobilized lipid to export energy to peripheral tissues as BHB for greater parity cows. Differences in concentrations among parity groups were marked at times, for ex le >0.20 mM in Ca for parity 1 and 2 to parity ≥5 and >0.33 mM for all older parities compared with parity 1 for P on the day of calving. The marked increase suggests profound differences in metabolism with increased parity are probably influenced, in part, by increased production. We found marked differences in concentrations of metabolites with parity that are consistent with reduced reproduction, health, and body condition for higher parity cows. These unfavorable differences in metabolism in Ca, P, glucose, and cholesterol concentrations for higher parity cows also complement the often-substantial differences in disease risk with parity and suggest a need to carefully consider the parity structure in study design. Managers and advisors will need to consider methods to reduce risk of health disorders tailored to cows of different ages.
Publisher: American Dairy Science Association
Date: 09-2014
Abstract: Our objectives were to evaluate the efficacy of icillin trihydrate for the treatment of metritis in dairy cows compared with ceftiofur hydrochloride and the subsequent effects on pregnancy at first insemination (P/AI). Cows in the first 12 d in milk (DIM) with a uterine discharge score of 5 (watery, reddish or brownish discharge of foul smell) and rectal temperature <39.5°C were diagnosed with metritis based on the fetid discharge, and cows with metritis and rectal temperature ≥39.5°C were diagnosed as having puerperal metritis. Cows with metritis (n=528) were blocked by parity and type of metritis as fetid discharge or puerperal metritis and, within each block, assigned randomly to receive 11mg/kg of icillin (n=259) or 2.2mg/kg of ceftiofur (n=269) once daily for 5 d. Day of diagnosis of metritis was considered study d 1. A cohort of 268 cows without metritis was selected randomly at 12 DIM. Rectal temperature was measured in cows with metritis on study d 1 to 7, and 12, and vaginal discharge was scored on study d 5, 7, and 12. Metritis cure was characterized by vaginal discharge score of <5 or by vaginal discharge score of <5 and no fever. At 32±3 DIM, vaginal discharge was scored for diagnosis of purulent vaginal discharge. At 39±3 DIM, endometrial cytology was performed. At 53±3 and 67±3 DIM, ovaries were scanned to determine estrous cyclicity. Pregnancy was evaluated after the first AI. Cure of metritis based on vaginal discharge <5 was greater for icillin than ceftiofur on d 5 (37.1 vs. 25.2%) and 7 (57.2 vs. 46.3%), but not on d 12 (82.0 vs. 85.0%). Cure of metritis based on vaginal discharge <5 and no fever was greater for icillin than for ceftiofur only on d 7 (50.4 vs. 37.9%), but not on d 5 (23.1 vs. 17.6%) and 12 (66.1 vs. 67.4%). Cows with puerperal metritis had reduced cure compared with cows with fetid discharge on d 5 (30.5 vs. 12.8%), 7 (55.2 vs. 33.6%), and 12 (72.0 vs. 61.1%). The proportion of cows with fever on any day after therapy started did not differ between treatments. Fifty-three percent of cows with metritis based on fetid discharge developed fever after initiating antimicrobial therapy. Cows receiving icillin had less prevalence of purulent vaginal discharge than those treated with ceftiofur (57.7 vs. 67.8%), but they were both greater than cows without metritis (21.9%). Prevalence of cytological endometritis did not differ between icillin and ceftiofur (30.0 vs. 25.4%), but they were both greater than cows without metritis (14.5%). The proportion of estrous cyclic cows (75.0%) and P/AI did not differ among treatments ( icillin=28.0% vs. ceftiofur=28.3% vs. without metritis=30.5%). Clinical cure was faster for icillin than for ceftiofur, but on study d 12 both treatments resulted in similar cure. Clinical cure was less for cows with puerperal metritis than for cows with fetid uterine discharge. Despite differences in uterine health, P/AI at the first insemination did not differ among treatments.
Publisher: American Dairy Science Association
Date: 2021
Publisher: American Dairy Science Association
Date: 03-2021
Publisher: Informa UK Limited
Date: 12-1998
Publisher: Wiley
Date: 13-11-2018
DOI: 10.1111/RDA.13363
Abstract: The objective was to compare pregnancy per artificial insemination (P/AI) with conventional (CS) or sex-sorted semen (SS) in dairy cows subjected to one of the three timed AI protocols. Cows (n = 356) were randomly assigned to synchronization with Ovsynch (OVS), Presynch-Ovsynch (PO) or Double-Ovsynch (DO) and inseminated on Day 77 ± 3 postpartum with either frozen-thawed SS (n = 182) or CS (n = 184) of the same bull. More cows were cyclic at the beginning of breeding Ovsynch increased (p < 0.01) with presynchronization and it was greater for DO than PO (OVS = 78.5%, PO = 85.1%, DO = 95.6%). Overall, P/AI for SS and CS increased with presynchronization (p < 0.05) on Days 31 (OVS = 35.5%, PO = 47.1%, DO = 48.3%) and 62 (OVS = 30.1%, PO = 43.8%, DO = 43.9%). Regardless of synchronization treatments, insemination with SS reduced P/AI (p < 0.02) on Days 31 (38.1% vs. 50.6%) and 62 (34.5% vs. 45.6%) compared with CS. No interaction was observed between synchronization treatment and type of semen for P/AI, although in cows receiving CS, P/AI was numerically greatest for PO (OVS = 42.0%, PO = 59.3%, DO = 49.0%), and in cows receiving SS, it was numerically greatest for those inseminated following DO (OVS = 27.9%, PO = 35.5%, DO = 47.6%). Thus, presynchronization improved P/AI in cows inseminated with sex-sorted or conventional semen.
Publisher: Bioscientifica
Date: 10-2016
DOI: 10.1530/REP-16-0104
Abstract: Elongation of the preimplantation conceptus is a prerequisite for successful pregnancy in ruminants and depends on histotroph secretion by the endometrium. Lipids are an essential component of the histotroph, and recent studies indicate that lipids have important roles in the elongation phase of conceptus development. The onset of elongation is marked by dynamic changes in the transcriptome of trophectoderm cells, which are associated with lipid metabolism. During elongation, the trophectoderm increases transcript expression of genes related to uptake, metabolism and de novo biosynthesis of fatty acids and prostaglandins. Expression of the gene PPARG increases substantially, and activation of the transcription factor PPARG by binding of lipid ligands appears to be crucial for the coordination of cell biology during elongation. Lipids accumulated in the epithelial cells of the endometrium during diestrus are likely the most important source of fatty acids for utilization by the conceptus and become available in the uterine lumen through exporting of exosomes, microvesicles, carrier proteins and lipoproteins. Targeting of uterine lipid metabolism and PPARG activity during preimplantation conceptus development through nutraceutical diets may be a good strategy to improve pregnancy survival and reproductive efficiency in ruminants.
Publisher: American Dairy Science Association
Date: 08-2019
Abstract: Metritis is a prevalent disease with effects on production, reproduction, and survival, thereby affecting dairy farm profitability. A component of the cost of metritis is antimicrobial therapy. Some antimicrobials result in milk withhold that adds to the cost of disease. The objectives were (1) to determine cost of metritis for 2 antimicrobial treatments using a herd budget that includes costs associated with incidence of concurrent diseases, milk production and reproduction losses, and removal from the herd and (2) to apply sensitivity analysis to determine the cost of different scenarios. Cows with metritis from a previous study assigned randomly to receive icillin (AMP, n = 259), an antimicrobial that requires milk withhold, or ceftiofur (CEFT, n = 269), an antimicrobial with no milk withhold, were used for the economic analysis. A group of cows with no metritis (NOMET, n = 268), matched by parity and calving day, served as the baseline for comparison. The incidence of other diseases in the first 60 d postpartum, culling and death, reproductive performance, discarded milk, milk yield, total milk sold per cow, and residual cow value were used as responses. The economic analysis considered the costs associated with therapy, reproductive management, discarded milk, estimated DM consumed, income from saleable milk, and the residual cow value at 300 d postpartum or earlier if the cow was removed from the herd. Sensitivity analyses were performed considering 3 scenarios for milk and feed prices. The incidence of diseases other than metritis (NOMET, 30.4% AMP, 45.4% CEFT, 34.0%) and days in the hospital (NOMET, 2.7 d AMP, 8.6 d CEFT, 3.5 d) were greater for cows treated with AMP than CEFT. Treatment did not affect the risk of leaving the herd (NOMET, 15.5% AMP, 15.0% CEFT, 19.1%). The 21-d pregnancy rate was lower for cows with metritis but did not differ between AMP and CEFT (NOMET, 24.9% AMP, 18.9% CEFT, 17.0%). Milk yield was greater for cows without metritis than those with metritis and greater for AMP than CEFT (NOMET, 33.7 kg/d AMP, 32.5 kg/d CEFT, 31.2 kg/d). Cost of metritis did not differ with choice of therapy, but it increased as milk price increased. When both milk and feed prices were the average values considered ($0.44/kg and $0.26/kg, respectively), the costs of a case of metritis for AMP and CEFT were, respectively, $344 and $410 when milk was discarded and $267 and $406 when milk was fed to calves. Cost of therapy for AMP and CEFT represented 16.6 and 24.6% of the total cost of metritis when milk was discarded and 21.5 and 24.8% of the total cost of metritis when milk was fed to calves. The largest component of cost of metritis for both therapies was the reduced income from milk minus feed cost, ranging from 40.0 to 56.7%. Collectively, metritis is an expensive disease, and choice of antimicrobial therapy did not influence survival, reproduction, or cost of the disease.
Publisher: American Dairy Science Association
Date: 03-2020
Abstract: Objectives were to evaluate the effect of prepartum energy intake and peripartal supplementation of ruminally protected choline (RPC) on select indicators of immune status in blood plasma and on lipopolysaccharide-stimulated blood cells ex vivo. At 47 ± 6 d before the expected calving date, 93 multiparous Holstein cows were assigned randomly to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement. Cows were fed energy to excess [EXE 1.63 Mcal of net energy for lactation (NE
Publisher: American Dairy Science Association
Date: 2020
Abstract: The objectives were to use meta-analytic methods to determine the effects of amount of supplemental choline ion as rumen-protected choline (RPC) starting prepartum on production and health of dairy cows. The literature was systematically reviewed and 21 experiments, with up to 66 treatment means and 1,313 prepartum parous cows, were included. All experiments had a treatment with no supplemental choline (0 g/d n = 30 treatment means), and the amount of choline ion supplemented to treated cows ranged from 5.6 to 25.2 g/d (n = 36 treatment means). Duration of pre- and postpartum feeding of RPC averaged (±standard deviation) 22.0 ± 6.0 and 57.5 ± 42.2 d, respectively. Data collected included the ingredient composition and chemical analyses of pre- and postpartum diets, amount of choline ion supplemented, number of cows per treatment, frequency of health events, and the least squares means and respective standard error of the means for production responses, liver composition, and blood parameters. The concentrations of net energy for lactation and metabolizable amino acids and protein (MP) in pre- and postpartum diets were predicted for each treatment mean using National Research Council (2001). Mixed model meta-analysis was conducted including the random effect of experiment and weighting by the inverse of the standard error of the means squared. Increasing supplementation of choline ion during transition linearly increased pre- (β = 0.0184 ± 0.00425) and postpartum dry matter intake (β = 0.0378 ± 0.00974), and yields of milk (β = 0.436 ± 0.112), energy-corrected milk (ECM β = 0.422 ± 0.0992), fat (β = 0.00555 ± 0.000793), and protein (β = 0.0138 ± 0.00378). Nevertheless, an interaction between choline and postpartum metabolizable methionine as a percent of MP (METMPPo) was observed for yields of milk, ECM, and protein because as METMPPo increased, the positive response to choline on yields of milk, ECM, and protein decreased. Supplementing choline during transition tended to reduce the risks of retained placenta and mastitis, but it had no effect on metritis, milk fever, displaced abomasum and ketosis, or the concentration of triacylglycerol in the hepatic tissue postpartum. The median amount of choline ion supplemented was 12.9 g/d and responses in postpartum dry matter intake and yields of milk, ECM, fat, and protein to that amount of supplementation were 0.5, 1.6, 1.7, 0.07, and 0.05 kg/d, respectively. No interactions were observed between supplemental choline and prepartum dietary net energy for lactation or metabolizable methionine as a percent of MP. Collectively, feeding RPC during the transition period improves performance in parous cows. Increases in yields of milk and milk components were observed in spite of pre- and postpartum diets, although the increments in milk, ECM, and protein yields with supplementing choline decreased as the concentration of methionine in postpartum diets increased. The optimum dose of choline ion was not detected, but likely it is more than the 12.9 g/d fed in most experiments evaluated in the current meta-analysis. Finally, the meta-analysis identified lack of sufficient data to understand the role of supplemental choline in nulliparous cows.
Publisher: Elsevier BV
Date: 03-2004
Publisher: American Dairy Science Association
Date: 03-2000
Publisher: Oxford University Press (OUP)
Date: 04-2016
DOI: 10.1095/BIOLREPROD.115.134908
Abstract: The objectives of this study were to characterize changes in transcriptome of preimplantation conceptuses at the onset of elongation and associated changes in uterine histotroph composition and endometrial physiology. Lactating dairy cows (n = 160) had their ovulation synchronized by artificial insemination (study Day 0). On Day 15, uteri were flushed and endometrium tissue collected. Recovered conceptuses were classified based on morphology/length as ovoid (1-4 mm), tubular (5-19 mm), and filamentous (20-60 mm). Total RNA (n = 48) was subjected to transcriptome analysis. The uterine fluid (n = 30) was evaluated by mass spectrophotometry. Transcriptome analyses revealed drastic changes in the transition from ovoid to tubular and from tubular to filamentous. Differentially expressed genes were associated with cellular movement, cell-to-cell signaling, cellular assembly and organization, lipid metabolism, small molecule biochemistry, and molecular transport. Specific changes included reorganization of cytoskeleton and cell migration, arginine metabolism, growth factors signaling, and lipid metabolism. Functional analysis revealed fatty acids and peroxisome proliferator activated receptor gamma as upstream regulators of transcriptome changes. Expression of PPARG increased 17-fold during the onset of elongation and was highly correlated with genes involved in lipid metabolism. The histotroph was rich in amino acids, lipids, saccharides, and other intermediate metabolites, and important changes in composition occurred in the presence of a conceptus. Pregnancy had a major impact on the concentrations of important lipids in the uterine fluid and expression of genes in the endometrium. Collectively, conceptus elongation involves remarkable changes in transcriptome, composition of the histotroph, and endometrial physiology, which help elucidate important events in uterine and conceptus biology at the onset of elongation.
Publisher: American Dairy Science Association
Date: 09-2007
Abstract: The objective was to determine if reducing the interval from presynchronization to the first GnRH injection (G1) of a timed artificial insemination (AI) protocol improves pregnancy per AI. One thousand two hundred fourteen Holstein cows, at 37 +/- 3 d in milk (DIM), were stratified by parity, DIM, and milk yield in the first month postpartum and randomly assigned to control (n = 412), 2 injections of PGF2alpha at 37 +/- 3 and 51 +/- 3 DIM, then enrolled in a timed AI protocol 14 d later PShort (n = 410), 2 injections of PGF2alpha at 40 +/- 3 and 54 +/- 3 DIM, then enrolled in a timed AI protocol 11 d later or PShortG (n = 392), same as PShort, but with an injection of GnRH 7 d before G1. All cows received the same timed AI protocol (d 65, G1 d 72, PGF2alpha d 73, 1 mg of estradiol cypionate d 75, AI). A subset of 1,000 cows had their ovaries examined by ultrasonography at G1 and 7 d later when PGF2alpha of the timed AI was given to determine presence of corpus luteum (CL) and ovulation to G1. Pregnancy was diagnosed on d 38 after timed AI, and pregnant cows were reevaluated for pregnancy 4 wk later. Altering the interval between presynchronization and G1 did not affect the proportion of cows with a CL at G1, but GnRH 7 d before G1 increased the proportion of cows with a CL. Ovulation to G1 was greater for 11 compared with the 14 d interval, but GnRH did not improve ovulation. The increased ovulation to G1 when the interval was reduced from 14 to 11 d was observed only in cows with a CL at G1, but treatment did not affect ovulation in cows without a CL at G1. Treatment affected the pregnancy per AI on d 38 and 66 after insemination, and they were greater for the 11 compared with 14-d interval, but addition of GnRH did not improve pregnancy per AI. Cows ovulating to G1 had greater pregnancy per AI regardless of whether or not they had a CL at G1. Reducing the interval from presynchronization to initiation of the timed AI protocol from 14 to 11 d increased ovulation to G1 and pregnancy per AI in lactating dairy cows.
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.THERIOGENOLOGY.2011.06.005
Abstract: High-producing dairy cows are subfertile. Hormonal and metabolic responses associated with homeorrhetic and homeostatic regulatory responses to partition nutrients for lactation, coupled with management, contribute to the reduction in fertility. Systems of reproductive management partially restore herd reproductive performance and provide a basis to access the impact of targeted nutritional strategies to further improve postpartum health and reproduction. Increasing the number of days feeding prepartum diets with a negative dietary cation-anion difference (DCAD), combined with adequate energy, protein, amino acids, and trace/macrominerals, improves the subsequent pregnancy rate. Likewise, supplementation of organic Se in the transition period and lactation improves immune function, uterine health, and subsequent reproductive performance under conditions of Se insufficiency. A basic understanding of the regulatory processes between nutrient partitioning and reproduction has led to the development of dietary strategies that benefit both lactation and reproduction. Postpartum increases in dietary nonstructural carbohydrates (i.e., glucogenic diets) increases ovarian activity in either intensive or extensive systems. Furthermore, sequential feeding of glucogenic-lipogenic diets enhances the proportion of cows pregnant by 120 d of lactation. Fatty acids of the n-6 and n-3 families act as nutraceuticals, altering innate immune responses and subsequent gene expression within the uterus to complement the sequential processes of follicle and embryo development and survival of the embryo and fetus. Selective or sequential feeding of lipogenic diets can benefit reproductive and immunological responses of lactating dairy cows and extensively managed beef cows.
Publisher: University of Florida George A Smathers Libraries
Date: 22-01-2019
Abstract: In the Southeast, milk is priced based on fat and skim milk value, with additional bonuses for somatic cell and bacterial counts. In recent years, butterfat has become more valuable. This 7-page document discusses some of the history behind the changes in milk fat consumption, management factors that influence milk fat content and yield by dairy cattle, and economic implications of changing fat content through the diet in two case scenarios. Written by José E. P. Santos and Albert De Vries, and published by the UF/IFAS Department of Animal Sciences, January 2019. n350
Publisher: American Dairy Science Association
Date: 10-2016
Abstract: Two experiments were conducted to characterize blood concentrations of minerals and acid-base status after oral dosing of Ca salts and to determine the effects of oral Ca on mineral and metabolic status and incidence diseases. The hypotheses were that administration of oral Ca as CaCl2 and CaSO4 maintains blood total Ca (tCa) concentrations ≥2.125 mM and reduces the incidence of diseases in early lactation. In experiment 1, 18 Holstein cows on the day of calving were assigned to receive a single dose of 0, 43, or 86g of Ca as an oral bolus. Blood was s led before and after treatments to characterize acid-base status and concentrations of minerals. In experiment 2, 450 Holstein cows considered of low (LRM normal calving) or high risk (HRM dystocia, twins, stillbirth, retained placenta, vulvo-vaginal laceration, or a combination of these) of metritis (primiparous-LRM=84 primiparous-HRM=84 multiparous-LRM=138 multiparous-HRM=138) on the day of calving were blocked by parity and then randomly assigned to control, no Ca supplementation 86g of Ca on d 0 and 1 postpartum (CaS1) or 86g of Ca on d 0 and 1 postpartum followed by 43g/d on d 2 to 4 postpartum (CaS4). Blood was s led before and 30 min after treatment on d 0, and 30 min after treatments on d 1 to 4, and d 7 and 10 for determination of concentrations of minerals and metabolites and blood acid-base responses. Disease incidence was evaluated for the first 30 DIM. Concentrations of ionized Ca (iCa) increased for 2h in cows supplemented with 43g of Ca and fewer than 8h in cows supplemented with 86g of Ca. The changes in iCa concentrations from pretreatment to 30 min after 86g of Ca supplemented on d 0 were 0.11±0.03 mM in multiparous cows and 0.25±0.03 mM in primiparous cows. Oral Ca reduced the incidence of subclinical hypocalcemia (SCH tCa <2.125mM) in the first 4 d in the experiment (control=69.3% CaS1=57.5% CaS4=34.2%). Calcium supplementation decreased the prevalence of SCH on d 0 and 1 postpartum in all cows. Stopping oral Ca in CaS1 on d 1 postpartum, however, caused a rebound in SCH on d 2 to 4 postpartum in primiparous cows. Oral Ca increased the incidence of metritis (control=22.7% CaS1=34.8% CaS4=32.8%), primarily because of an increase in LRM primiparous cows (control=17.9% CaS1=35.7% CaS4=42.9%). Oral Ca increased morbidity in primiparous cows (control=38.1% CaS1=61.8% CaS4=60.3%) but had no effect on multiparous cows (control=38.2% CaS1=35.1% CaS4=30.1%). Large doses of oral Ca as salts of chloride and sulfate in the first days postpartum should be avoided in primiparous cows and used only in cows at risk of clinical hypocalcemia.
Publisher: American Dairy Science Association
Date: 10-2016
Abstract: The objectives of this experiment were to determine the effects of oral Ca supplementation on milk yield, body condition, pregnancy per artificial insemination (P/AI), and days to pregnancy in Holstein cows considered to be of low (LRM no calving assistance, live singleton without retained placenta) or high (HRM at least one of the following: dystocia, twins, stillbirth, retained placenta, or vulvo-vaginal laceration) risk of developing metritis. The hypotheses were that oral Ca supplementation during the early postpartum period would reduce the loss of body condition and improve lactation performance and reproduction. Four hundred fifty Holstein cows were blocked by parity as primiparous cows (n=174) or multiparous cows (n=276). Within parity, a cow considered at HRM was matched with a cow of LRM and the pair was randomly assigned to control (no Ca supplementation), 86g of Ca on d 0 and 1 postpartum (CaS1), or 86g of Ca on d 0 and 1 postpartum followed by 43g/d on d 2 to 4 postpartum (CaS4). Body condition was scored at calving and 32 d postpartum and estrous cyclicity was evaluated at 38 and 52 d postpartum. Milk yield was recorded daily. Multiparous cows were classified as above or below the mean 305-d mature equivalent milk yield based on production in the previous lactation. Reproductive performance was evaluated for the first 210 d postpartum. Body condition did not differ among treatments, and cows lost on average 0.44 units of body condition in the first month of lactation. Calcium supplementation did not affect milk yield in the first 5 mo postpartum. For multiparous cows, Ca supplementation was beneficial to milk yield in the first 30 DIM in cows of greater production potential, but detrimental to multiparous cows with below average production potential. Calcium supplementation to primiparous cows reduced P/AI at first (control=55.8, CaS1=31.5, CaS4=37.0%) and all artificial inseminations (control=48.5, CaS1=34.6, CaS4=38.5%) however, Ca supplementation to multiparous cows improved P/AI at the first (control=32.1, CaS1=38.6, CaS4=41.3%) and all artificial inseminations (control=28.1, CaS1=35.3, CaS4=40.5%). These responses in P/AI to Ca supplementation resulted in extended median days to pregnancy (control=75, CaS1=100, CaS4=94 d) and smaller proportion of pregnant cows (control=89.3, CaS1=83.9, CaS4=83.9%) in primiparous cows, but shorter days to pregnancy (control=115, CaS1=94, CaS4=94 d) and increased proportion of pregnant cows in multiparous cows (control=67.0, CaS1=77.2, CaS4=74.3%). Risk of metritis depressed most measures of reproduction evaluated in the experiment. Results indicate that responses to oral Ca supplementation are conditional on parity and production potential of cows. Oral Ca supplementation was detrimental to reproduction in primiparous cows. On the other hand, Ca supplementation benefited reproduction in multiparous cows and milk yield in the cohort of multiparous cows of greater production potential.
Publisher: American Dairy Science Association
Date: 11-2023
Publisher: American Dairy Science Association
Date: 08-2008
Abstract: The objectives were to evaluate the effect of synchronization protocols on follicular development and estradiol 17-beta (E(2)) and progesterone (P(4)) concentrations in dairy heifers. In experiment 1, 36 heifers were assigned to 1 of 6 synchronization protocols in a 3 x 2 factorial design: presynchronization with GnRH on study d -6 or -9 [study d 0 = initiation of the Cosynch + CIDR (controlled internal drug releasing insert containing P(4)) protocol] or no presynchronization (control) and one injection of PGF(2 alpha) or not on study d 0. In experiment 2, 126 heifers were assigned to 1 of 4 synchronization protocols in a 2 x 2 factorial arrangement: presynchronization or not with GnRH on study d -6 and injection of PGF(2 alpha) or not on study d 0. In experiments 1 and 2, all heifers received a modified Cosynch protocol with CIDR for 7 d starting on study d 0. After the PGF(2 alpha) of the Cosynch and removal of the CIDR, heifers were detected in estrus and inseminated. Those not inseminated by study d 10 received an injection of GnRH and were timed-inseminated. Ovaries were scanned by ultrasound on d 0, 2, and 5, daily from d 7 to 14, and on d 16. Blood s les collected on d 0, 2, 7, 9, and 16 were analyzed for P(4), and the blood s le collected on d 9 was analyzed for E(2). Pregnancy was diagnosed at 28 and 40 +/- 3 d after artificial insemination. In experiment 1, there was a tendency for the presynchronization protocol to affect the proportion of heifers ovulating in response to the first GnRH injection of the Cosynch + CIDR protocol. In experiment 2, a greater proportion of presynchronized heifers ovulated in response to the first GnRH injection. Although heifers receiving PGF(2 alpha) had larger ovulatory follicles on d 7 and before ovulation and shorter intervals to estrus and ovulation, these heifers tended to have decreased concentrations of E(2) during proestrus. Presynchronization of dairy heifers with GnRH increased ovulation in response to the first GnRH injection, and treatment of heifers with PGF(2 alpha) at initiation of the Cosynch + CIDR protocol increased the size of the ovulatory follicle and reduced the intervals to estrus and ovulation.
Publisher: American Dairy Science Association
Date: 12-2012
Abstract: In this prospective cohort study, Holstein cows considered to be at high risk of developing metritis (dystocia, twins, stillbirth, retained placenta, or their combination) were matched with herdmates at low risk of developing metritis (normal calving) and monitored daily for rectal temperature and uterine discharge during the first 12 d in milk (DIM). Blood was s led on d 0, 1, and 3 postpartum for assessment of neutrophil phagocytic and oxidative burst activities. Blood was also s led at 0, 1, 2, 3, 4, 7, and 12 DIM for determination of serum concentrations of Ca, K, Mg, nonesterified fatty acids, β-hydroxybutyrate, and glucose. On the basis of receiver operator characteristic curves, subclinical hypocalcemia (SCH) was defined as a serum Ca concentration ≤8.59 mg/dL in at least 1 s le in the first 3 DIM. The overall incidences of metritis and puerperal metritis were 47.3 and 30%, respectively. Concentration in blood and percentages of neutrophils undergoing phagocytosis and oxidative burst were all reduced in cows with SCH compared with normocalcemic cows. Cows with SCH were at a greater risk of developing fever, metritis, and puerperal metritis compared with normocalcemic cows. Among cows at low risk of developing metritis, those with SCH had a greater incidence of metritis (40.7%) compared with normocalcemic cows (14.3%). Similarly, among cows at high risk of developing metritis, cows with SCH had a greater incidence of metritis (77.8%) compared with normocalcemic cows (20.0%). Cows with SCH had elevated concentrations of nonesterified fatty acids and β-hydroxybutyrate compared with normocalcemic cows. The relative risk of developing metritis decreased by 22% for every 1mg/dL increase in serum Ca. Neither metritis nor SCH influenced the resumption of estrous cyclicity by 38 DIM, but cows with SCH had a reduced pregnancy rate and a longer interval to pregnancy compared with normocalcemic cows. Finally, the population risk to develop uterine diseases attributable to SCH was 66.6% for metritis and 91.3% for puerperal metritis in the present study.
Publisher: American Dairy Science Association
Date: 06-2016
Abstract: The main objective was to evaluate the association between vulvovaginal laceration and uterine diseases in dairy cows. The secondary objectives were to evaluate the association between vulvovaginal laceration and cyclicity, and reproductive performance. The vulvovaginal region of 660 Holstein cows from a 5,000 lactating-cows herd was inspected at 4d in milk (DIM) for the presence of lacerations, and scored (VLS) as follows: 0=no laceration 1=laceration <2cm at the dorsal commissure of the vulva or lateral walls of the vulva/vagina 2=laceration ≥2cm at the dorsal commissure of the vulva or at the lateral walls of the vulva/vagina, or both. Vaginal discharge was scored at 4, 6, and 8 DIM for diagnosis of metritis, and then at 32 DIM for diagnosis of purulent vaginal discharge (PVD). Data were analyzed using LOGISTIC and PHREG procedures of SAS. Cows with VLS 2 had greater incidence of metritis than cows with VLS 0 (69.1 vs. 42.4%), and cows with VLS 1 tended to have greater incidence of metritis than cows with VLS 0 (52.0 vs. 42.4%). Cows with VLS 2 had greater incidence of PVD than cows with VLS 0 (56.5 vs. 43.1%). A lower proportion of cows with VLS 2 than VLS 0 were cyclic by 64 DIM (70.0 vs. 86.8%). A lower proportion of cows with VLS 2 than VLS 0 were pregnant at 60 d after first AI (28.7 vs. 33.6%). Proportion of pregnant cows at 60d after AI tended to be lower for VLS 1 than VLS 0 (28.4 vs. 33.6%). Hazard of pregnancy by 300 DIM was not affected by VLS. Hazard of pregnancy was decreased for cows with metritis, PVD, and anovular cows. In summary, vulvovaginal laceration was associated with uterine disease and cyclicity, which were negatively associated with reproductive performance. Vulvovaginal laceration was recognized as a risk factor for postpartum uterine disease.
Publisher: American Dairy Science Association
Date: 2018
Abstract: Meta-analytic methods were used to determine statistical relationships between metabolizable AA supplies and milk protein yield, milk protein percentage, and milk yield in lactating dairy cows. Sixty-three research publications (258 treatment means) were identified through a search of published literature using 3 search engines and met the criteria for inclusion in this meta-analysis. The Cornell Net Carbohydrate and Protein System (CNCPS) version 6.5 was used to determine dietary nutrient parameters including metabolizable AA. Two approaches were used to analyze the data. First, mixed models were fitted to determine whether explanatory variables predicted responses. Each mixed model contained a global intercept, a random intercept for each experiment, and data were weighted by the inverse of the SEM squared. The second analysis approach used classical effect size meta-analytical evaluation of responses to treatment weighted by the inverse of the treatment variance and with a random effect of treatment nested within experiment. Regardless of the analytical approach, CNCPS-predicted metabolizable Met (g/d) was associated with milk protein percentage and yield. Milk yield was positively associated with CNCPS-predicted metabolizable His, Leu, Trp, Thr, and nonessential AA (g/d). Milk true protein yield was also associated with CNCPS-predicted metabolizable Leu (g/d). Predicted metabolizable Lysine (g/d) did not increase responses in production outcomes. However, mean metabolizable Lys supply was less than typically recommended and the change with treatment was minimal (157 vs. 162 g 6.36 vs. 6.38% metabolizable protein). Experiments based solely on Lys or Met interventions were excluded from the study database. It is possible that the inclusion of these experiments may have provided additional insight into the effect of these AA on responses. This meta-analysis supports other research indicating a positive effect of Met and His as co-limiting AA in dairy cows and suggests Leu, Trp, and Thr be given greater consideration in future research.
Publisher: American Dairy Science Association
Date: 06-2002
Publisher: American Dairy Science Association
Date: 02-2023
Publisher: American Dairy Science Association
Date: 07-2014
Abstract: The objective of this retrospective observational cohort study, combined with simulation, was to evaluate the effect of extending the voluntary waiting period (VWP) during the summer on profitability on a Florida dairy farm. Data from Holstein cows (n=1,416) that calved between June and September of 2007 and 2008 were used. Cows that calved between June 1 and July 21 (regular group REG n=719) were artificially inseminated (AI) for the first time upon estrus detection (ED) after the second PGF₂α of the Presynch protocol administered between 57 and 63 d in milk (DIM), or underwent timed AI using the Ovsynch protocol (TAI) if not detected in estrus. Cows that calved between July 22 and September 18 (extended group EXT n=697) underwent AI for the first time after the first or second PGF₂α starting November 14 or November 21 or underwent TAI if not detected in estrus. For second and subsequent AI, all cows underwent AI upon ED or enrolled on TAI after nonpregnancy diagnosis. Following these schemes, average VWP in the REG group and EXT group were 60 and 83 d, respectively. Overall profitability for both experimental and subsequent parities were calculated by subtracting the costs existing of feeding costs ($0.30/kg lactating cow diet $0.25/kg dry cow diet), breeding costs ($2.65/dose PGF₂α $2.40/dose GnRH $0.25/injection administration $10/semen straw $5/AI $3 regnancy diagnosis), and other costs ($3/d) from the daily revenues with milk sales ($0.44/kg of milk), cow sales ($1.76/kg of live weight), and calf sales ($140/calf). A herd budget simulation was used to predict future cash flow after culling or end of subsequent parity until 6 yr after the start of the study to account for all cash flow consequences of extended VWP. Cows in the EXT group had greater first-service pregnancy per AI (PAI1) but still had greater days open and calving interval. Delaying breeding did not affect total cash flow because the EXT group had greater combined profitability for the experimental parity and subsequent parity but lesser future cash flow. Delayed breeding during the summer increased PAI1 but did not improve overall reproductive efficiency and did not affect overall profitability.
Publisher: Wiley
Date: 28-01-2014
DOI: 10.1111/RDA.12280
Abstract: The aim of this study was to compare pregnancy per artificial insemination (P/AI) after timed AI with sex-sorted sperm (SS) or conventional semen (CS) in lactating dairy cows. Cyclic cows (n = 302) were synchronized by Ovsynch and randomly assigned into two groups at the time of AI. Cows with a follicle size between 12 and 18 mm and clear vaginal discharge at the time of AI were inseminated with either frozen-thawed SS (n = 148) or CS (n = 154) of the same bull. A shallow uterine insemination was performed into the uterine horn ipsilateral to the side of probable impending ovulation. Pregnancy per AI on Day 31 tended (p = 0.09) to be less for SS (31.8%) than CS (40.9%). Similarly, P/AI on Day 62 was less (p = 0.01) for cows inseminated with SS (25.7%) compared with CS (39.0%). The increased difference in fertility between treatments from Days 31 to 62 was caused by the greater (p = 0.02) pregnancy loss for cows receiving SS (19.2%) than CS (4.8%). Cow parity (p = 0.02) and season (p < 0.01) when AI was performed were additional factors affecting fertility. Primiparous cows had greater P/AI than multiparous cows both on Day 31 (41.7% vs 25.0% in SS and 53.0% vs 31.8% in CS groups) and on Day 62 (33.3% vs 20.5% in SS and 48.5% vs 31.8% in CS groups). During the hot season of the year, P/AI on Day 31 was reduced (p = 0.01) in the SS group (19.6%) when compared with the rates during the cool season (38.1%). In conclusion, sex-sorted sperm produced lower fertility results compared to conventional semen even after using some selection criteria to select most fertile cows.
Publisher: Elsevier BV
Date: 12-2022
Publisher: American Dairy Science Association
Date: 2015
Abstract: The study was designed to evaluate the effects of altering the ratio between n-6 and n-3 fatty acids (FA) in the diet and the intake of these FA by lactating dairy cows on lactation performance and inflammatory acute phase responses to a challenge with lipopolysaccharide (LPS). Multiparous Holstein cows (n=45) were blocked based on milk yield from d 6 to d 10 postpartum and, within each block, assigned randomly to 1 of 3 dietary treatments at 14d postpartum treatments lasted for 90d. Diets were supplemented with a mixture of Ca salts of fish, safflower, and palm oils to create 3 different ratios of n-6 to n-3 FA namely, 3.9, 4.9, or 5.9 parts of n-6 to 1 part of n-3 FA (R4, R5, and R6, respectively). During the first 5 wk of the study, blood was s led weekly and analyzed for concentrations of metabolites and hormones. On d 75 postpartum, cows received an infusion of 10µg of LPS into one quarter of the mammary gland to evaluate inflammatory acute phase responses. Altering the ratio of dietary n-6 to n-3 FA was reflected in changes in the FA composition of plasma and milk fat. Reducing the ratio of n-6 to n-3 FA from R6 to R4 increased dry matter intake (24.7, 24.6, and 26.1±0.5kg/d for R6, R5, and R4, respectively), with concurrent increases in yields of 3.5% fat-corrected milk (43.4, 45.4, and 48.0±0.8kg/d), milk fat (1.53, 1.60, and 1.71±0.03kg/d), milk true protein (1.24, 1.28, and 1.32±0.02kg/d), and milk lactose (2.12, 2.19, and 2.29±0.04kg/d). After the LPS challenge, concentrations of IL-6 in plasma increased as the ratio of n-6 to n-3 FA increased (112.5, 353.4, and 365.1±86.6pg/mL for R4, R5, and R6, respectively). Elevations of body temperature and somatic cell count were greater for cows fed R5 compared with those fed R4 or R6 (41.3, 40.8, and 40.8±0.2°C 4.33, 3.68, and 3.58±0.25×10(6)/mL, for R5, R4, and R6, respectively). Haptoglobin concentration was greatest at 24h after LPS challenge for cows fed R6. Phagocytosis and oxidative burst by neutrophils collected from circulation were unaffected by dietary treatment in the first 48h after intramammary LPS infusion. In conclusion, supplying the same quantity of FA in the diet of early lactation dairy cows but altering the ratio of the polyunsaturated FA of the n-6 to n-3 families influenced lactation performance and inflammatory responses to an LPS challenge.
Publisher: American Dairy Science Association
Date: 03-2012
Abstract: The objective was to examine the associations of peripartum concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and calcium with milk production in early lactation and pregnancy at the first artificial insemination (AI) across different management systems. Fifty-five Holstein freestall dairy herds located across the United States and Canada were visited weekly for blood s le collection from 2,365 cows. For each week of s ling (from wk -1 through wk 3 relative to calving) and for each metabolite, serum concentrations were dichotomized at various thresholds to identify the thresholds with the best negative associations with milk production and pregnancy at first AI. These thresholds were used to categorize the serum concentrations into higher and lower risk categories. Repeated-measures ANOVA and multivariable logistic regression were conducted for milk production and pregnancy at the first AI data, respectively, considering cow as the experimental unit and herd as a random effect. In the week before calving, serum NEFA ≥ 0.5 mEq/L, BHBA ≥ 600 μmol/L, and calcium ≤ 2.1 mmol/L were associated with 1.6 to 3.2 kg/d milk loss across the first 4 Dairy Herd Improvement Association (DHIA) milk tests. High levels of NEFA and BHBA in wk 1 and 2 after calving (≥ 0.7 and ≥ 1.0 mEq/L for NEFA, and ≥ 1,400 and ≥ 1,200 μmol/L for BHBA), and low levels of calcium (≤ 2.1 mmol/L) in wk 1, 2 and 3 after calving were associated with milk loss at the first DHIA milk test. Serum concentrations of NEFA and BHBA were not associated with pregnancy at first AI in any s ling week, whereas calcium <2.2 to 2.4 mmol/L from wk 1 through wk 3 postpartum were associated with reduced pregnancy at first AI. In conclusion, high serum concentrations of NEFA, BHBA, and low concentrations of calcium around parturition were associated with early lactation milk loss, and low calcium concentration around parturition was associated with impaired early lactation reproduction.
Publisher: American Dairy Science Association
Date: 03-2010
Abstract: Our objective was to determine the effect of exogenous progesterone (P4) during a timed artificial insemination (TAI) protocol on pregnancies per AI (P/AI) in dairy cows not previously detected in estrus. Lactating cows (n=3,248) from 7 commercial dairy herds were submitted to a presynchronization protocol (2 injections of PGF(2alpha) 14 d apart Presynch), and cows in estrus after the second PGF(2alpha) received AI (EDAI n=1,583). Cows not inseminated by 12 to 14 d after the second PGF(2alpha) injection were submitted to a TAI protocol (GnRH on d 0, PGF(2alpha) on d 7, and GnRH+TAI 72h after PGF(2alpha)). At onset of the TAI protocol, cows were balanced by parity and days in milk and assigned randomly to receive no exogenous P4 (control, n=803) or a controlled internal drug release (CIDR) insert containing 1.38g of P4 from d 0 to 7 (CIDR, n=862). Blood s les were collected at the second PGF(2alpha) injection of the Presynch and on the day of the first GnRH injection of the TAI protocol for P4 determination. When P4 in both s les was or=1 ng/mL were classified as cyclic. Concentration of P4 at 11 to 14 d after AI was determined in a subgroup of cows (n=453) from 2 herds. Pregnancy was diagnosed at 40+/-5 and 65+/-5 d after AI. Proportion of cows inseminated on estrus after the second PGF(2alpha) injection of the Presynch protocol differed among herds (range=26.7 to 59.8%). Overall P/AI for EDAI cows at 40+/-5 and 65+/-5 d were 36.2 and 33.7%, respectively, and pregnancy loss was 8.8%. Proportion of cyclic cows at the onset of the TAI protocol differed among herds (range from 66.5 to 86.3%), but did not differ between treatments (control=72.4%, CIDR=74.1%). Treatment affected P/AI at 40+/-5 (control=33.3%, CIDR=38.1%) and 65+/-5 (control=30.0%, CIDR=35.1%) d after AI but did not affect pregnancy loss (8.6%). Cyclic cows had greater P/AI at 40+/-5 (38.2 vs. 29.3%) and 65+/-5 d (35.1 vs. 26.1%) after AI, but cyclic status had no effect on pregnancy loss. Treatment affected P4 concentration after AI, with more CIDR cows having P4 >or=1 ng/mL (94.4 vs. 86.9%) and P4 >or=3.2 ng/mL (81.8 vs. 68.0%) at 11 to 14 d after AI compared with control cows. Treatment of cows not previously detected in estrus with a CIDR insert during a TAI protocol increased proportion of cows with functional CL after AI and P/AI.
Publisher: American Dairy Science Association
Date: 10-2012
Abstract: The objective was to identify herd-level indicators expressed as a proportion of s led animals with increased nonesterified fatty acids (NEFA) or β-hydroxybutyric acid (BHBA), or decreased calcium in wk -1 and wk +1 relative to calving that were associated with herd-level incidence of retained placenta, metritis and displaced abomasum, milk production, and probability of pregnancy at the first artificial insemination (AI). Fifty-five Holstein freestall dairy herds in the United States and Canada were visited weekly. Blood was collected from 2,365 cows around parturition, and serum concentrations of NEFA, BHBA, and calcium were determined. Different cow-level metabolite thresholds associated with detrimental health or productivity in previous studies were used to classify animals into high- and low-risk metabolite concentration groups. For wk -1 and wk +1 relative to calving, a herd-level threshold was determined as the proportion of s led animals in the high-risk metabolite concentration groups with the strongest association with increased incidence of disease, milk loss, or decreased pregnancy at the first AI. The odds of displaced abomasum after calving were higher in herds that had ≥ 25% of the animals with BHBA ≥ 1,400 μmol/L in wk +1 [odds ratio (OR)=2.1 95% confidence interval (CI)=1.0-4.2)] or ≥ 35% of the animals with calcium ≤ 2.1 mmol/L in wk +1 (OR=2.4 CI=1.3-4.3). Herd-level thresholds of ≥15% of the cows with BHBA ≥ 800 μmol/L in wk -1 and ≥ 15% of the cows with calcium ≤2.1mmol/L in wk +1 were associated with milk loss (±SE) of 4.4±1.7 and 3.8 ± 1.4 kg/d per cow, respectively. When only multiparous cows were considered, herds with ≥30% of the multiparous cows with NEFA ≥0.5 mEq/L in wk -1 were associated with a 3.0 ± 1.5 kg/d per cow milk loss. The odds of pregnancy at first AI were lower in herds that had ≥ 5% of the cows with calcium ≤ 2.1 mmol/L in wk -1 (OR=0.7 CI=0.5-1.0), or ≥ 30% of the cows with NEFA ≥ 1.0 mEq/L (OR=0.6 CI=0.4-0.9) or ≥ 25% of the cows with calcium ≤2.1 mmol/L in wk +1 (OR=0.7 CI=0.5-0.9). When only multiparous cows were considered, the odds of pregnancy at first AI were lower in herds that had ≥50% of multiparous cows with NEFA ≥0.5 mEq/L in wk -1 (OR=0.5 CI=0.2-0.9). In conclusion, several herd-level thresholds for the proportion of cows with increased NEFA or BHBA, or decreased calcium in the week before and after calving were associated with higher risk of displaced abomasum, milk loss at the first Dairy Herd Improvement Association test, and decreased pregnancy at first AI. The association found between precalving BHBA and milk production is promising due to the availability of several cow-side tests for measuring BHBA. Some of the herd-level associations differed from the previously described cow-level associations, suggesting the potential of interpreting periparturient metabolic challenges at the herd level, where changes in diet and management are generally implemented.
Publisher: American Dairy Science Association
Date: 09-2010
Abstract: The objective was to compare the costs of natural service (NS) and timed artificial insemination (TAI) as breeding programs for dairy cows. Both programs were directly compared in a field study from November 2006 to March 2008. Reproductive results in that study were similar and served as inputs for this study. A herd budget accounting for all costs and revenues was created. Net cost during the field study for the NS program was $100.49/cow per year and for the TAI program was $67.80/cow per year, unadjusted for differences in voluntary waiting period for first insemination (VWP) and pregnancy rates (PR). After inclusion of the differences in VWP and PR, the economic advantage of the TAI program was $9.73/cow per year. Costs per day a cow was eligible for insemination were estimated at $1.45 for the NS program and $1.06 for the TAI program. Sensitivity analysis revealed that if the marginal feed cost increased to $5/hundredweight (cwt 1 cwt=45.36kg), the advantage of TAI increased to $48.32/cow per year. In addition, higher milk prices and greater genetic progress increased the advantage of TAI. When semen price increased from $6 to $22, the NS program had an economic advantage of $33.29/cow per year. If each NS bull was replaced by an additional cow, the advantage of the TAI program was $60.81/cow per year. Setting the PR for both programs at 18% and the VWP at 80 d resulted in an advantage of $37.87/cow per year for the TAI program. In conclusion, any advantage of TAI depended greatly on cost to feed bulls, semen price, and genetic merit of semen.
Publisher: Elsevier BV
Date: 2004
DOI: 10.1016/S0093-691X(03)00241-3
Abstract: The objective of this study was to evaluate ovarian function after inducing ovulation with a deslorelin implant in nonlactating dairy cows and heifers. Cattle received GnRH on Day -9, and PGF2alpha on Day -2. On Day 0, in Experiment 1, cows received either 100 microg GnRH (Control), a 750 microg (DESLORELIN 750) or 1000 microg (DESLORELIN 1000) deslorelin implant. On Day 0, in Experiment 2, cows received 100 microg of GnRH or a 450 microg (DESLORELIN 450) deslorelin implant. In Experiments 1 and 2, cows received PGF2alpha on Day 16. Ultrasonography and blood s ling for plasma progesterone (P4) were used to monitor ovarian activity. On Day 0, in Experiment 3, heifers received either 100 microg of GnRH or 750 microg (DESLORELIN 750) deslorelin implant. On Day 16, all heifers received PGF2alpha. Blood s les were collected on Days 7, 13 and 16. In Experiments 1-3, deslorelin implants did not elevate plasma concentrations of P4 in a systematic manner during the late luteal phase. In Experiments 1 and 2, deslorelin implants decreased the size of the largest follicle and the number of Class II and III follicles. In Experiments 1 and 2, deslorelin-treated cows failed to ovulate by Day 28. In conclusion, deslorelin implants induced ovulation, stimulated development of a normal CL, and delayed follicular growth during the subsequent diestrus period. For future applications, the dose of the deslorelin implant will have to be adjusted, and if used for timed-inseminations, nonpregnant cows will have to be resynchronized to minimize delayed returns to estrus and ovulation.
Publisher: American Registry of Professional Animal Scientists
Date: 10-2004
Publisher: American Dairy Science Association
Date: 06-2014
Abstract: The objective of the current study was to evaluate the effect of GnRH early postpartum on induction of ovulation, uterine health, and fertility in dairy cows. Holstein cows without a corpus luteum (CL) at 17 ± 3 DIM were assigned randomly to receive i.m. GnRH (n = 245) at 17 ± 3 and 20 ± 3 DIM or remain as controls (n = 245). Ovaries were scanned by ultrasonography twice weekly totaling 4 examinations. Ovulation was characterized by the appearance of a CL ≥ 20 mm at any ultrasound or CL <20mm in 2 consecutive examinations. Clinical and cytological endometritis were diagnosed at 35 DIM. Compared with control, GnRH increased ovulation up to 3.5d after the last treatment (78.7 vs. 45.0%) and did not affect the prevalence of clinical endometritis (23.9 vs. 18.6%) or cytological endometritis (30.9 vs. 32.8%). Prevalence of clinical endometritis increased in cows that had calving problems (32.6 vs. 15.9%) and metritis (40.6 vs. 15.8%). Metritis increased prevalence of cytological endometritis (50.7 vs. 23.5%). Treatment with GnRH did not affect pregnancy per artificial insemination at 32 (37.6 vs. 38.6%) or 74 d after artificial insemination (35.0 vs. 31.5%), but reduced pregnancy loss (6.8 vs. 18.1%). No overall effect of GnRH treatment on hazard of pregnancy was observed however, an interaction between GnRH treatment and ovulation showed that GnRH-treated cows that ovulated had increased hazard of pregnancy by 300 DIM compared with GnRH-treated and control cows that did not ovulate (hazard ratio=2.0 and 1.3, respectively), but similar to control cows that ovulated (hazard ratio=1.1). Gonadotropin-releasing hormone early postpartum induced ovulation without affecting uterine health, but failed to improve pregnancy per artificial insemination or time to pregnancy, although it reduced pregnancy loss.
Publisher: American Dairy Science Association
Date: 02-2023
Publisher: American Dairy Science Association
Date: 12-1998
Publisher: American Dairy Science Association
Date: 11-2009
Abstract: The objective of this study was to compare reproductive performance of lactating dairy cows bred by natural service (NS) or timed AI (TAI). One thousand fifty-five cows were blocked by parity and enrolled to receive either NS or TAI. Cows in both groups were presynchronized with 2 injections of PGF(2alpha) given at 42 and 56 d postpartum. Fourteen days after the last PGF(2alpha) injection, cows in the TAI group were enrolled in an Ovsynch protocol (d 0 GnRH 7 d later, PGF(2alpha) 56 h after PGF(2alpha) injection, second dose of GnRH and 16 h after second GnRH cows were TAI). Cows in the TAI group were resynchronized with an intravaginal insert containing progesterone inserted 18 d after TAI and removed 7 d later when GnRH was given. Cows were examined by ultrasonography on d 32 after TAI nonpregnant cows received PGF(2alpha) and GnRH 56 h later followed by TAI 16 h after the GnRH injection. Nonpregnant cows in TAI group were reinseminated up to 5 times using the same scheme. Cows in the NS group were exposed to bulls 14 d after the second PGF(2alpha) injection, and ultrasonography was performed 42 d after exposure to bulls to determine pregnancy status. Nonpregnant cows in the NS group were reexamined by transrectal palpation combined with ultrasound every 28 d until diagnosed pregnant or 223 d postpartum, whichever occurred first. Cows diagnosed pregnant in TAI or NS were reconfirmed 28 d later to determine pregnancy loss. All bulls underwent an evaluation of breeding soundness and were rested for 14 d after 14 d of cow exposure. Health disorders were evaluated up to 70 d postpartum, and body condition score was evaluated at d 70 postpartum. Blood was collected on d 56 and 65 postpartum and analyzed for progesterone to determine cyclicity. The proportion of pregnant cows in the first 21 d of breeding did not differ between groups. The overall 21-d cycle pregnancy rate (PR), which included a total of 8 and 5 service opportunities for NS and TAI, respectively, was not different between groups (25.7 and 25.0% for NS and TAI, respectively). The daily rate of pregnancy was 15% greater for NS than TAI because cows in NS had a greater PR, which resulted in fewer median days open (111 vs. 116 d). Proportion of pregnant cows at 223 d postpartum was greater in the NS than TAI group (84.2 vs. 74.8%, respectively). Cyclicity did not affect reproductive performance. Cows with body condition score >/=2.75 had greater proportion of pregnant cows in the first 21 d of breeding and daily PR in the first 223 d postpartum Primiparous cows had greater proportion of pregnant cows and daily PR than multiparous cows at 223 d postpartum. In conclusion, the greater proportion of pregnant cows in the NS group was attributed to more opportunities for breeding than in the TAI group.
Publisher: American Dairy Science Association
Date: 09-2010
Abstract: Objectives were to determine effects of feeding pomegranate extract (POMx) rich in polyphenols on performance, health, nutrient digestion, and immunocompetence of calves in the first 70 d of age. Holstein calves (n=67), at 2+/-1 d of age (d 0=birth day) were randomly assigned to 0 (control), 5 (POMx5), or 10 g/d (POMx10) of pomegranate extract containing 16.9% gallic acid equivalent (GAE) to result in intakes of 0, 850 and 1,700 mg of GAE/d or an average of approximately 0, 15, and 30 mg of GAE/kg of body weight (BW) per day. All calves received colostrum during the first 24 h, pasteurized milk thereafter until 61 d of age, and grain was fed ad libitum for the first 70 d of age. Calves were housed in in idual hutches, and grain intake, attitude and fecal scores, incidence and duration of health disorders, and treatments for health problems were evaluated daily. Body weight was measured on 2 consecutive days at 2, 30, and 70 d of age and averaged for each measurement. Concentrations of glucose and 3-hydroxybutyrate were measured in plasma. Nutrient digestion was measured using total fecal collection during a 3-d period. Neutrophil phagocytic and killing activities and antibody response to immunization with ovalbumin were measured. Peripheral blood mononuclear cells were cultured and cytokine production measured. Feeding POMx had no effect on intake or BW gain in the first 30 d of age, but after 30 d of age, both grain dry matter intake and BW gain decreased with increasing addition of POMx, which resulted in calves that were 1.8 and 4.3 kg lighter at 70 d of age for POMx5 and POMx10, respectively, compared with controls. Feeding POMx did not influence dry matter, organic matter, or starch digestibility, but it reduced crude protein and fat digestion. Plasma concentrations of glucose and 3-hydroxybutyrate were similar among treatments throughout the first 70 d of age. Measures of calf health such as fecal and attitude scores, risk of fever, and rectal temperature were not altered by treatments. Similarly, neutrophil phagocytic and killing activities did not differ among treatments. On the contrary, feeding POMx increased synthesis of interferon-gamma and interleukin-4 by peripheral blood mononuclear cells and improved total immunoglobulin G responses to ovalbumin vaccination. These results suggest that feeding POMx top-dressed onto the grain suppresses intake of grain and digestibility of fat and protein, likely because of the high tannin content. Nevertheless, polyphenols from POMx enhanced mitogen-induced cytokine production and response to vaccination, which might benefit immune competence of calves and potentially health. Additional studies are warranted to minimize the effect of POMx on intake and digestibility and to better understand the mechanisms by which polyphenols improve immune response of calves.
Publisher: American Dairy Science Association
Date: 02-2018
Abstract: Objectives were to evaluate the effect of prepartum energy intake on performance of dairy cows supplemented with or without ruminally protected choline (RPC 0 or 17.3 g/d of choline chloride 0 or 60 g/d of ReaShure, Balchem Corp., New H ton, NY). At 47 ± 6 d before the expected calving date, 93 multiparous Holstein cows were assigned randomly to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement. Cows were fed energy to excess [EXE 1.63 Mcal of net energy for lactation/kg of dry matter (DM)] or to maintenance (MNE 1.40 Mcal of net energy for lactation/kg of DM) in ad libitum amounts throughout the nonlactating period. The RPC was top-dressed for 17 ± 4.6 d prepartum through 21 d postpartum (PP). After calving, cows were fed the same methionine-balanced diet, apart from RPC supplementation, through 15 wk PP. Liver was biopsied at -14, 7, 14, and 21 d relative to parturition. Cows fed EXE or MNE diets, respectively, consumed 40 or 10% more Mcal/d than required at 15 d before parturition. Cows fed the MNE compared with the EXE diet prepartum consumed 1.2 kg/d more DM postpartum but did not produce more milk (41.6 vs. 43.1 kg/d). Thus, PP cows fed the EXE diet prepartum were in greater mean negative energy balance, tended to have greater mean concentrations of circulating insulin, fatty acids, and β-hydroxybutyrate, and had greater triacylglycerol in liver tissue (8.3 vs. 10.7% of DM) compared with cows fed the MNE diet prepartum. Cows fed RPC in transition tended to produce more milk (43.5 vs. 41.3 kg/d) and energy-corrected milk (44.2 vs. 42.0 kg/d) without increasing DM intake (23.8 vs. 23.2 kg/d) during the first 15 wk PP, and tended to produce more milk over the first 40 wk PP (37.1 vs. 35.0 kg/d). Energy balance of cows fed RPC was more negative at wk 2, 3, and 6 PP, but mean circulating concentrations of fatty acids and β-hydroxybutyrate did not differ from those of cows not fed RPC. Despite differences in energy balance at 2 and 3 wk PP, mean concentration of hepatic triacylglycerol did not differ between RPC treatments. Feeding RPC reduced the daily prevalence of subclinical hypocalcemia from 25.5 to 10.5%, as defined by concentrations of total Ca of <8.0 mg/dL in serum in the first 7 d PP. Pregnancy at first artificial insemination tended to be greater for cows fed RPC (41.3 vs. 23.6%), but the proportion of pregnant cows did not differ by 40 wk PP. Heifers born from singleton calvings from cows fed RPC tended to experience greater daily gain between birth and 50 wk of age than heifers from cows not supplemented with RPC. Feeding RPC for approximately 38 d during the transition period tended to increase yield of milk for 40 wk regardless of amount of energy consumed during the pregnant, nonlactating period.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.THERIOGENOLOGY.2016.05.032
Abstract: The objectives of this study were to evaluate factors affecting in vivo embryo production and pregnancy per embryo transfer (P/ET) in Holstein cattle in the southeast region of the United States. Data from a total of 516 embryo collections and 10,297 ETs performed from 2011 to 2014 were available. For embryo production, the effects of donor parity (nulliparous [N], primiparous [P], multiparous [M]), average temperature-humidity index (THI) at embryo collection, days in milk at embryo collection, occurrence of calving problems, and occurrence of metritis postpartum were evaluated. For P/ET, the effects of donor parity (N or parous), recipient parity (N, P, and M), embryo type (fresh, frozen, IVF, and IVF-frozen), embryo developmental stage (4-7), embryo quality (1-3), recipient estrous cycle day at ET (6-9), average THI at ET, days in milk at ET, milk yield at ET, occurrence of calving problems (abortion, dystocia, twins, fetal death, or retained placenta), and occurrence of metritis postpartum were evaluated. Pregnancy was diagnosed at 41 ± 3 days of gestation. Continuous and binary data were analyzed using the MIXED and GLIMMIX procedures of SAS, respectively. Parity affected embryo production M had greater number and percentage of unfertilized embryos and lesser percentage of viable embryos than P and N. Recipient parity, embryo type, embryo stage, embryo quality, estrous cycle day at ET, and THI at ET affected P/ET. There was an interaction between recipient parity and THI at ET. P/ET was greater for N than P and greater for P than M, greater for fresh embryos than others, greater for stage 7 than others, greater for quality 1 than 2 and greater for quality 2 than 3, and greater for ET on estrous cycle Day 7 and 8 than 6. P/ET was decreased for THI ≥80 in N and THI ≥72 in P and M. Calving problems and metritis also affected P/ET in P and M and was lesser for cows that had calving problems and metritis. In conclusion, embryo production was affected by donor parity, and P/ET was affected by embryo type, embryo stage, embryo quality, recipient estrous cycle day at ET, THI, calving problems, and metritis.
Publisher: American Dairy Science Association
Date: 08-2021
Abstract: The objective was to investigate the economic effect of treating dairy cows with metritis using ceftiofur-free acid or leaving them untreated at the time of diagnosis. Cows with a fetid, watery, red-brownish vaginal discharge were diagnosed with metritis (d 0). Data from 875 dairy cows (506 primiparous and 369 multiparous) from 1 herd in northern Florida that had been part of a larger study evaluating different treatments for metritis were used for the economic analysis. Holstein cows with metritis had been randomly assigned to: Ceftiofur (CEF, n = 239) = subcutaneous injection of 6.6 mg/kg of ceftiofur crystalline-free acid in the base of the ear at d 0 and d 3 Untreated (UNT, n = 233) = no treatment applied at metritis diagnosis. Both groups could receive escape therapy if condition worsened. A group of nonmetritic healthy cows (NMET n = 403) from the same cohort was randomly selected for comparison. Continuous outcomes such as 300-d milk production (kg/cow), milk sales ($/cow), cow sales ($/cow), treatment cost by 60 days in milk ($/cow), reproduction cost ($/cow), replacement cost ($/cow), feeding cost ($/cow), and gross profit per cow ($/cow) were analyzed using the ANOVA (MIXED procedure of SAS version 9.4). Dichotomous outcomes such as pregnancy and culling by 300 d were analyzed using logistic regression (GLIMMIX procedure of SAS). Models included the fixed effects of treatment, parity, and the interaction between treatment and parity. A stochastic analysis was performed with 10,000 iterations using the observed results from each group. The CEF treatment resulted in greater treatment cost by 60 DIM than UNT ($112 vs. $37), but resulted in a greater proportion of pregnant cows (71 vs. 61%) and decreased culling by 300 DIM (29 vs. 39%) compared with UNT. Gross profit was lesser for UNT than NMET ($2,969 vs. $3,426), and CEF was intermediate ($3,219). The stochastic analysis showed that the mean difference in gross profit between UNT and NMET was -$457 saleable milk (49%) and replacement cost (24%) accounted for most of the variation. The mean difference in gross profit between CEF and NMET group was -$207 saleable milk (82%) and initial metritis treatment cost (9%) accounted for most of the variation. The mean difference in gross profit between the UNT and the CEF group was -$250 replacement cost (41%) and cow sales (31%) accounted for most of the variation. In summary, metritis caused large economic losses when left untreated, and CEF reduced those losses by improving fertility, reducing culling and replacement cost, and reducing milk yield losses.
Publisher: Bioscientifica
Date: 09-2022
DOI: 10.1530/REP-22-0032
Abstract: Bovine granulosa cells need to be cultured with serum to generate inflammation in response to bacterial lipopolysaccharide. This study shows that it is cholesterol that facilitates this lipopolysaccharide-stimulated cytokine secretion. During bacterial infections of the bovine uterus or mammary gland, ovarian granulosa cells mount inflammatory responses to lipopolysaccharide (LPS). In vitro , LPS stimulates granulosa cell secretion of the cytokines IL-1α and IL-1β and the chemokine IL-8. These LPS-stimulated inflammatory responses depend on culturing granulosa cells with serum, but the mechanism is unclear. Here, we tested the hypothesis that cholesterol supports inflammatory responses to LPS in bovine granulosa cells. We used granulosa cells isolated from 4 to 8 mm and .5 mm diameter ovarian follicles and manipulated the availability of cholesterol. We found that serum or follicular fluid containing cholesterol increased LPS-stimulated secretion of IL-1α and IL-1β from granulosa cells. Conversely, depleting cholesterol using methyl-β-cyclodextrin diminished LPS-stimulated secretion of IL-1α, IL-1β and IL-8 from granulosa cells cultured in serum. Follicular fluid contained more high-density lipoprotein cholesterol than low-density lipoprotein cholesterol, and granulosa cells expressed the receptor for high-density lipoprotein, scavenger receptor class B member 1 (SCARB1). Furthermore, culturing granulosa cells with high-density lipoprotein cholesterol, but not low-density lipoprotein or very low-density lipoprotein cholesterol, increased LPS-stimulated inflammation in granulosa cells. Cholesterol biosynthesis also played a role in granulosa cell inflammation because RNAi of mevalonate pathway enzymes inhibited LPS-stimulated inflammation. Finally, treatment with follicle-stimulating hormone, but not luteinising hormone, increased LPS-stimulated granulosa cell inflammation, and follicle-stimulating hormone increased SCARB1 protein. However, changes in inflammation were not associated with changes in oestradiol or progesterone secretion. Taken together, these findings imply that cholesterol supports inflammatory responses to LPS in granulosa cells.
Publisher: American Dairy Science Association
Date: 2001
Publisher: American Dairy Science Association
Date: 03-2019
Abstract: The objectives were to use meta-analytic methods to determine the effects of changes in dietary cation-anion difference (DCAD) prepartum on productive performance and health of dairy cows. The literature was systematically reviewed, searching randomized experiments with transition cows that manipulated the prepartum DCAD or experiments with acidogenic diets in which dietary Ca, P, or Mg was manipulated. Forty-two experiments, including 134 treatment means and 1,803 cows, were included in the meta-analysis. Of those, 5 experiments with 15 treatment means reported responses for 151 nulliparous cows. Data collected included the mineral composition of prepartum diets, parity group prepartum, breed, days on treatment, and means and respective measure of variance for urine pH, dry matter intake (DMI), body weight, body condition, productive performance, concentrations of minerals and metabolites in blood, and incidence of diseases. Mixed effects meta-analyses were conducted weighting by the inverse of standard error of the means squared to account for the precision of each experiment. Models include the effects of DCAD, parity group prepartum, interaction between DCAD and parity group, and other covariates that showed significance in univariable analysis. Final models were selected based on parsimony and model fit. Reducing the prepartum DCAD reduced intake prepartum but improved intake postpartum in both parity groups. Interactions between DCAD and parity group occurred for yields of milk, fat-corrected milk (FCM), fat, and protein because reducing the DCAD improved those responses in parous cows however, reducing the DCAD either had no effect on yields of milk and protein or reduced the yield of FCM and fat in nulliparous cows. The resulting equations from the statistical models predicted that reducing the DCAD from +200 to -100 mEq/kg would increase blood total Ca on the day of calving from 1.86 to 2.04 ± 0.05 mM, DMI postpartum 1.0 kg/d, and milk yield 1.7 kg/d in parous cows. The increased concentrations of blood total Ca at calving and postpartum explained the marked reduction in risk of milk fever in parous cows with a reduction in DCAD. As the DCAD decreased, the risk of retained placenta and metritis also decreased, resulting in fewer disease events per cow in both nulliparous and parous cows. Dietary concentrations of Ca, P, or Mg prepartum had no effect on DMI or yields of milk and FCM however, increasing dietary Ca within the study range of 0.16 to 1.98% of dry matter tended to increase the risk of milk fever in parous cows regardless of DCAD fed. Collectively, results support the recommendation of prepartum acidogenic diets to result in a negative DCAD to parous cows with improvements in lactation performance and reduced risk of diseases however, the range of DCAD fed did not allow for detection of an optimum value for postpartum performance. On the other hand, despite improvements in blood concentrations of Ca and reduction in uterine diseases with a reduction in DCAD fed to nulliparous cows, productive performance was either depressed or unaffected and the limited number of experiments did not provide sufficient evidence for a recommended DCAD for this group of cows.
Publisher: American Dairy Science Association
Date: 06-2006
Publisher: American Dairy Science Association
Date: 09-2018
Abstract: The objective was to determine if the reduction in dry matter (DM) intake of acidogenic diets is mediated by inclusion of acidogenic products, content of salts containing Cl, or changes in acid-base status. The hypothesis was that a decrease in intake is mediated by metabolic acidosis. Ten primigravid Holstein cows at 148 ± 8 d of gestation were used in a duplicated 5 × 5 Latin square design. The dietary cation-anion difference (DCAD) of diets and acid-base status of cows were manipulated by incorporating an acidogenic product or by adding salts containing Cl, Na, and K to the diets. Treatments were a base diet (T1 1.42% K, 0.04% Na, 0.26% Cl DCAD = 196 mEq/kg) the base diet with added 1% NaCl and 1% KCl (T2 1.83% K, 0.42% Na, 1.23% Cl DCAD = 194 mEq/kg) the base diet with added 7.5% acidogenic product, 1.5% NaHCO
Publisher: Frontiers Media SA
Date: 07-04-2022
DOI: 10.3389/FANIM.2022.847574
Abstract: The objectives of this study were to evaluate the associations between residual dry matter (DM) intake or residual feed intake (RFI) from 1 to 15 weeks postpartum and concentrations of metabolites in plasma in early lactation and reproduction in Holstein cows. Data from 9 experiments, including 851 cows, were used. Intake of DM, milk yield, and body weight were evaluated daily, whereas milk composition and body condition were evaluated twice weekly for the first 105 days postpartum. Blood was s led on the day of calving and again on days 7, 14, and 21 postpartum and analyzed for concentrations of non-esterified fatty acids (FA), β-hydroxybutyrate (BHB), and glucose. Reproduction was evaluated for the first 300 days postpartum. Residual DM intake was calculated as the observed minus the predicted intake, with intake predicted based on a model that accounted for major energy sinks. Cows were ranked and categorized into RFI quartiles, from the smallest (Q1) to the largest (Q4) RFI (−1.87, −0.46, 0.39, and 1.90 kg/day). Increasing efficiency (i.e., from Q4 to Q1) resulted in linear decreases in DM intake (Q1 to Q4 18.9, 20.4, 21.3, and 22.7 kg/day), and median days open (132, 125, 135, and 147 d). Conversely, improving efficiency was associated with a linear increase in pregnancy per artificial insemination (AI, 31.4, 30.6, 31.2, and 24.5%) and quadratic increases in the 21-day cycle pregnancy rate (21.2, 21.1, 22.0, and 16.6%) and the proportion of pregnant cows (79.0, 80.7, 82.4, and 71.5%). The estimated net energy for lactation (NEL) content of diets increased linearly with improved RFI (1.88, 1.76, 1.71, and 1.58 Mcal/kg), resulting in no association between RFI and energy-corrected milk yield or body energy change. Nevertheless, increased feed efficiency was associated with a linear increase in concentrations of blood FA (0.68, 0.63, 0.60, and 0.59 m M ), but a quadratic association with BHB (0.75, 0.64, 0.64, and 0.65 mM), with no association with glucose. Collectively, the most feed efficient cows ate 3.8 kg/day less DM, produced the same amount of energy-corrected milk, and had improved reproductive performance compared with the least efficient cows, thus suggesting that the underlying mechanisms responsible for improved feed efficiency might also be linked with improvements in reproduction.
Publisher: American Dairy Science Association
Date: 07-2010
Abstract: Objectives were to determine the effect of reducing the period of follicle dominance in a timed artificial insemination (AI) protocol on pregnancy per AI (P/AI) in Holstein cows. In experiment 1, 165 cows received 2 injections of PGF(2alpha) at 36 and 50 d in milk (DIM). At 61 DIM, cows were assigned randomly to Cosynch 72 h (CoS72: d 61 GnRH, d 68 PGF(2alpha), d 71 GnRH) or to a 5-d Cosynch 72 h with 1 (5dCoS1: d 61 GnRH, d 66 PGF(2alpha), d 69 GnRH) or 2 injections of PGF(2alpha) (5dCoS2: d 61 GnRH, d 66 and 67 PGF(2alpha), d 69 GnRH). Blood was s led at the first GnRH, first PGF(2alpha), and at the second GnRH of the protocols and assayed for progesterone. Ovulatory responses to GnRH were evaluated by ultrasonography. Cows were considered synchronized if they had concentrations of progesterone >or=1 ng/mL and <1 ng/mL on the days of the PGF(2alpha), and the second GnRH of the protocols, respectively, and if they ovulated within 48 h of the second GnRH injection. In experiment 2, 933 cows were assigned randomly to CoS72 or 5dCoS2. Blood was assayed for progesterone and ovaries were scanned as in experiment 1. Plasma on the days of the first PGF(2alpha) and final GnRH of the timed AI protocols was assayed for estradiol in 75 cows. Pregnancy was diagnosed on d 38 and 66 after AI. In experiment 1, the proportions of cows with corpora lutea (CL) regression on the day of AI differed and were 79.0, 59.1, and 95.7% for CoS72, 5dCoS1, and 5dCoS2, respectively. Cows that ovulated to the first GnRH of the Cosynch tended to have lesser CL regression than cows that did not ovulate (73.0 vs. 86.4%). Protocol synchronization differed between treatments and they were greater for CoS72 (69.4%) and 5dCoS2 (78.4%) than for 5dCoS1 (42.3%). In experiment 2, CL regression was lesser (91.5 vs. 96.3%) but detection of estrus at timed AI (30.9 vs. 23.6%) was greater for CoS72 than 5dCoS2, and cows in estrus had increased P/AI (46.2 vs. 31.9%). Cows in CoS72 ovulated a larger follicle and had greater concentrations of estradiol on the day of AI than cows in 5dCoS2, but protocol synchronization tended to increase in cows receiving the 5dCoS2. When all 933 cows were evaluated, P/AI was greater for 5dCoS2 than for CoS72 (37.9 vs. 30.9%). Similarly, when only cows with progesterone <1 ng/mL on the day of AI were evaluated, P/AI was greater for 5dCoS2 than for CoS72 (39.3 vs. 33.9%). Treatment with PGF(2alpha) on d 5 and 6 after GnRH resulted in increased luteolysis and allowed for reducing the interval from GnRH to timed AI, which increased P/AI. Reducing time of follicle dominance in timed AI protocols improves fertility of lactating dairy cows.
Publisher: American Dairy Science Association
Date: 04-2015
Abstract: A systematic review of the literature was performed with the objective to evaluate the effects of progesterone supplementation using a single intravaginal insert during timed artificial insemination (AI) programs on fertility in lactating dairy cows. A total of 25 randomized controlled studies including 8,285 supplemented cows and 8,398 untreated controls were included in the meta-analysis. Information regarding the presence of corpus luteum (CL) at the initiation of the synchronization protocol was available for 6,883 supplemented cows and 6,879 untreated controls in 21 experiments. Studies were classified based on service number (first AI vs. resynchronized AI), use of presynchronization (yes vs. no), and insemination of cows in estrus during the synchronization protocol (inseminated in estrus and timed AI vs. timed AI only). Reproductive outcomes of interest were pregnancy per AI (P/AI) measured on d 32 (27 to 42) and 60 (41 to 71) after AI, and pregnancy loss between d 32 and 60 of gestation. Random effects meta-analyses were conducted and treatment effect was summarized into a pooled risk ratio with the Knapp-Hartung modification (RRK+H). The effect of moderator variables was assessed using meta-regression analyses. Progesterone supplementation increased the risk of pregnancy on d 32 [RRK+H = 1.08 95% confidence interval (CI) = 1.02-1.14] and 60 after AI (RRK+H = 1.10 95% CI = 1.03-1.17). The benefit of progesterone supplementation was observed mainly in cows lacking a CL at the initiation of the timed AI program (d 60: RRK+H = 1.18 95% CI = 1.07-1.30) rather than those with CL (d 60: RRK+H = 1.06 95% CI = 0.99-1.12). Progesterone supplementation benefited P/AI in studies in which all cows were inseminated at timed AI (d 60: RRK+H = 1.20 95% CI = 1.10-1.29), but not in studies in which cows could be inseminated in estrus during the timed AI program (d 60: RRK+H = 1.04 95% CI = 0.92-1.16). Progesterone supplementation tended to reduce the risk of pregnancy loss (RRK+H = 0.84 95% CI = 0.67-1.00). Service number and presynchronization did not influence the effect of progesterone supplementation on fertility. In summary, progesterone supplementation using a single intravaginal insert during the timed AI program increased P/AI mostly in cows without CL and reduced the risk of pregnancy loss in lactating dairy cows. Insemination of cows in estrus during the synchronization protocol eliminated the benefit of supplemental progesterone on P/AI.
Publisher: American Dairy Science Association
Date: 11-2013
Abstract: Objectives were to determine the effects of GnRH at the initiation of the 5-d timed artificial insemination (AI) program combined with 2 injections of PGF2α on ovarian responses and pregnancy per AI (P/AI) in dairy heifers, and the role of progesterone concentrations on LH release and ovulation in response to GnRH. In study 1, heifers received a controlled internal drug release (CIDR) insert containing 1.38 g of progesterone on d 0, an injection of 25 mg of PGF2α and CIDR removal on d 5, and an injection of 100 μg GnRH concurrently with AI on d 8. Heifers were assigned to receive no additional treatment (control n=559) or an injection of GnRH on d 0 and a second injection of PGF2α on d 6 (G2P n=547). In study 2, all heifers were treated as described for the control in study 1, and were allocated to receive no additional treatment (control n=723), an injection of PGF2α on d 6 (NG2P n=703), or an injection of GnRH on d 0 and an injection of PGF2α on d 6 (G2P n=718). In study 3, heifers received a CIDR on d 7 after ovulation and were assigned randomly to a low-progesterone (LP n=6) treatment in which 2 injections of 25 mg of PGF2α each were administered 12h apart, on d 7 and 7.5 after ovulation, or to a high-progesterone (HP n=12) treatment in which no PGF2α was administered. On d 8, heifers received 100 μg of GnRH and blood was s led at every 15 min from -30 to 180 min relative to the GnRH for assessment of LH concentrations. Additionally, 94 heifers were assigned to LP or HP and ovulation in response to GnRH was evaluated. In study 1, P/AI was greater for G2P than for the control on d 32 (59.4 vs. 53.5%) and 60 after AI (56.6 vs. 51.3%). In study 2, administration of GnRH on d 0 increased the proportion of heifers with a new corpus luteum on d 5 (control=21.9 vs. NG2P=20.1 vs. G2P=34.4%). Administration of a second PGF2α increased the proportion of heifers with progesterone <0.5 ng/mL at AI (control=83.1 vs. NG2P=93.0 and G2P=87.2%). Pregnancy per AI was greater for G2P than for control and NG2P on d 32 (control=52.9 vs. NG2P=55.0 vs. G2P=61.7%) and 60 (control=49.0 vs. NG2P=51.6 vs. G2P=59.1%). In study 3, HP attenuated LH release and reduced ovulation (19.0 vs. 48.4%) in response to GnRH compared with LP. Combining GnRH and 2 doses of PGF2α in the 5-d timed AI protocol improved follicle turnover, luteolysis, and P/AI in heifers. Elevated concentrations of progesterone suppressed LH release and are linked with the low ovulatory response to the initial GnRH treatment of the protocol.
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.TVJL.2015.03.001
Abstract: The objectives of this study were to determine the effect of mineral/energy supplementation of dairy cows with dystocia on blood mineral concentrations, energetic and inflammatory profiles, and milk yield. Multiparous Holstein cows with dystocia were randomly assigned into two groups, (1) treated with a mineral/energy supplement (DME, n= 18) and (2) not treated (DNT, n= 22). A group of cows with normal parturition were randomly selected and were left untreated (NNT, n= 25). Cows in DME received an oral drench of 110 g of calcium and 400 g of propionate as calcium propionate plus 110 g potassium chloride and 150 g of magnesium sulfate administered within 6 h of calving and again 3 days post-partum. Compared to cows with a normal parturition, dystocic cows had decreased plasma calcium concentrations, increased plasma haptoglobin, decreased milk yield at 1 day post-partum, and tended to have increased rectal temperatures from 1 to 12 days post-partum. Compared with cows in DNT, those in DME had decreased plasma calcium concentrations and increased plasma magnesium concentrations 2 and 3 days post-partum, and a tendency for an increase in rectal temperature from 1 to 12 days post-partum. Dystocia is detrimental to calcium homeostasis post-partum, but mineral/energy supplementation as undertaken in this study is not recommended for use in cows with dystocia.
Publisher: Editora Scienza
Date: 15-10-2019
Publisher: Elsevier BV
Date: 2001
DOI: 10.1016/S0093-691X(00)00447-7
Abstract: Developments in the use of drugs to improve reproduction and embryo production have focused on estrus and ovulation synchronization protocols and embryonic survival. Protocols for synchronization of ovulation eliminate the need for detection of estrus and allow timed insemination of all cows enrolled. Various estrogenic, progestational, GnRH and PGF2 alpha-like drugs are used to synchronize follicle development, CL regression and induction of ovulation. Strategies are discussed to optimize such programs to maximize herd pregnancy rates. Use of bovine Somatotrophin (bST) in combination with the Ovsynch protocol resulted in increased pregnancy rates, indicating possible effects on oocyte and embryonic development. Treatment of embryo donor cows with bST reduced the proportion of unfertilized oocytes and increased the number of transferable embryos. Furthermore, bST increased pregnancy rate when given to the recipient. Sub-luteal plasma progesterone concentrations after insemination have been associated with lower pregnancy rates. Injection of hCG on day 5 post-insemination resulted in induction of an accessory CL, increased plasma progesterone concentrations and increased conception rates. Strategies involving the use of sustained GnRH agonists to enhance CL development and alter follicular development are considered for future programs to enhance pregnancy rates.
Publisher: American Dairy Science Association
Date: 2015
Abstract: The objective was to evaluate the effect of feeding increasing amounts of essential fatty acids (FA) in milk replacer (MR) during the first 60 d of life on growth, health, and immunity of Holstein calves. Calves were born from dams fed low concentrations of total and essential FA during the lasT2 mo of pregnancy. Newborn calves were blocked by sex and parity of the dam and assigned randomly to receive 1 of 4 MR treatments (T). Hydrogenated coconut oil and soybean oil were mixed with emulsifier and commercial MR powder to prepare the following 4 MR containing 0.119 and 0.007 (T1), 0.187 and 0.017 (T2), 0.321 and 0.036 (T3), and 0.593 and 0.076 (T4) g of intake per kg of metabolic body weight (BW(0.75)) of linoleic acid and α-linolenic acid, respectively. At 30 d of life, concentrations of essential FA (linoleic acid and α-linolenic acid) in liver increased, whereas concentrations of C12:0, C14:0, C16:0, and C20:3n-9 decreased linearly with increasing intake of essential FA. Body weight gain and feed efficiency were optimized when male calves consumed T2, whereas gain by female calves tended to increase linearly with increasing intake of essential FA during the first 30 d of age. However, these responses to treatment were not maintained after initiation of concentrate feeding at 31 d of life. Over the 60-d preweaning period, wither and hip heights were improved in both sexes as intake of essential FA increased up to T3. Some measures of health and immunity were affected by replacing some coconut oil with soybean oil. Severity of diarrhea tended to decrease linearly plasma concentrations of haptoglobin during diarrhea were lower in T2, T3, and T4 phagocytosis by blood neutrophils tended to peak for calves fed T2 in vitro proliferation of stimulated blood lymphocytes was greater for calves fed T2 in vitro stimulated blood cells produced more IFN-γ (up to T3 for males and T2 for females), concentrations of serum IgG against ovalbumin injections were increased in males fed T2 or T3 and skin-fold thickness increased in response to an intradermal antigen injection of all calves fed up to T4. Across sex and under the conditions of the present study, mean daily intakes of linoleic acid between 3 to 5g/d and intakes of α-linolenic acid between 0.3 and 0.6g/d during the first 30 d of life promoted growth of preweaned Holstein calves, possibly by improving their immune status.
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.ANIREPROSCI.2007.12.005
Abstract: Objectives were to evaluate progesterone concentrations after cows had initiated estrous cycles following calving and induction of estrous cycles in postpartum anovular high-producing Holstein dairy cows treated with controlled internal drug releasing (CIDR). In experiment 1 (EXP1), 62 cows that had initiated estrous cycles received a new CIDR (NCIDR) containing 1.38 g of progesterone or a 7-d used autoclaved CIDR (UCIDR) 48h after luteolysis for 7 d. Ovaries were examined by ultrasonography, and plasma analyzed for concentrations of progesterone. In experiment 2 (EXP2), 515 cows diagnosed as anestrus were randomly assigned to untreated control, NCIDR or UCIDR for 6d. Plasma was analyzed for concentration of progesterone 12 d after CIDR removal to determine ovulation. In EXP1, milk yield and body condition did not influence progesterone concentrations. Concentration of progesterone tended to increase faster (P=0.10) in cows receiving UCIDR than NCIDR, but both treatments reached a plateau at 90min. Cows receiving the NCIDR had greater (P=0.04) concentrations of progesterone during the 7-d treatment, but they were mostly subluteal (<1.0 ng/mL) after d 2. After removal, concentrations of progesterone were greater for NCIDR than UCIDR for the first 45 min, and were similar thereafter. Multiparous cows had lesser (P=0.004) concentrations than primiparous cows throughout the study. The pattern of ovarian follicular development was not affected by treatment. In EXP2, induction of onset of estrous cycles increased (P<0.01) with progesterone treatments, but was similar between NCIDR and UCIDR. Proportion of cows experiencing shorter than typical length estrous cycles after first AI tended to be greater (P=0.09) for control cows than those receiving the CIDR, and for cows remaining anestrous than those in which onset of estrous cycles was induced. Pregnancy per AI and pregnancy loss were similar among treatments. Cows that resumed estrous cyclicity prior to first AI had greater (P=0.01) pregnancy per AI. Treatment of high-producing Holstein cows that had previously initiated onset of estrous cycles with CIDR resulted in subluteal concentrations of progesterone, but in anestrous high-producing cows increased induction of estrous cycles with no effect on fertility at first insemination.
Publisher: Bioscientifica
Date: 07-2019
DOI: 10.1530/REP-19-0037
Abstract: Metritis is associated with reduced fertility in dairy cows, but the mechanisms are unclear because the disease resolves several weeks before insemination. One hypothesis is that metritis causes persistent changes in granulosa cells during follicle development, which might be evident in the transcriptome of granulosa cells from dominant follicles weeks after parturition. To test this hypothesis, we collected the follicular fluid and granulosa cells from dominant follicles 63 days post partum from cows previously diagnosed with metritis, at least 6 weeks after resolution of the disease and from cows not diagnosed with metritis (control cows). Bacterial lipopolysaccharide was detected in follicular fluid, and concentrations were associated with follicular fluid IL-8 and glucose concentrations. Transcriptome analysis using RNAseq revealed 177 differentially expressed genes in granulosa cells collected from cows that had metritis compared with control cows. The most upregulated genes were ITLN1 , NCF2 , CLRN3 , FSIP2 and ANKRD17 , and the most downregulated genes were ACSM1 , NR4A2 , GHITM , CBARP and NR1I3 . Pathway analysis indicated that the differentially expressed genes were involved with immune function, cell–cell communication, cell cycle and cellular metabolism. Predicted upstream regulators of the differentially expressed genes included NFκB, IL-21 and lipopolysaccharide, which are associated with infection and immunity. Our data provide evidence for a persistent effect of metritis on the transcriptome of granulosa cells in ovarian follicles after the resolution of disease.
Publisher: Elsevier BV
Date: 11-2003
DOI: 10.1016/S0093-691X(03)00117-1
Abstract: The objectives of the present study were to determine the effects of resynchronization with GnRH on Day 21 after artificial insemination (AI) on pregnancy rate and losses of pregnancy in lactating dairy cows. Holstein cows (n=585) on two dairy farms were assigned to one of two treatments in a randomized complete block design. On Day 21 after a pre-enrollment AI, animals assigned to the resynchronization (RES) group received 100 microg of GnRH i.m., whereas animals in the control (CON) group received no treatment. All animals were examined ultrasonographically on Days 21 and 28 after AI, and blood s les were taken for progesterone measurement on Day 21. Pregnancy was diagnosed on Day 28 and reconfirmed 14 days later. Nonpregnant cows on Day 28 were inseminated using timed AI after the completion of the Ovsynch protocol 10 and 17 days after enrollment in the study for RES and CON groups, respectively. Progesterone concentration > or =2.35 ng/ml was used as an indicator of pregnancy on Day 21. For RES and CON cows, pregnancy rate at Days 21 (70.9% versus 73.0%, P<0.56), 28 (33.1% versus 33.6% P<0.80) and 42 (27.0% versus 26.8% P<0.98) after the pre-enrollment AI did not differ. Administration of GnRH on Day 21 after AI had no effect on pregnancy loss in RES and CON groups from days 21 to 28 (53.2% versus 53.5% P<0.94) and days 28 to 42 (17.9% P<0.74) after AI. Pregnancy rate after the resynchronization period was similar for both treatment groups. Resynchronization with GnRH given on Day 21 after AI for initiation of a timed AI protocol prior to pregnancy diagnosis does not affect pregnancy rate and pregnancy loss in lactating dairy cows.
Publisher: American Dairy Science Association
Date: 05-2023
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.THERIOGENOLOGY.2015.09.052
Abstract: The objective was to decrease the reinsemination interval (RI) when dairy cows and heifers are inseminated using all timed artificial insemination (TAI) programs. Holstein cows (n = 211) and heifers (n = 153) were randomly assigned to a control or 21-day Resynch (21dRES) at 13 days after TAI. Animals in 21dRES (n = 109 cows and 77 heifers) had a progesterone device inserted on Day 13 and removed on Day 20 after TAI and ovaries scanned by ultrasonography. Animals found not to have an active CL (<15 mm) or a CL that decreased 10 mm or greater from Days 13 to 20, and to have a follicle of 12 mm or greater received GnRH and TAI on Day 21. Pregnancy diagnosis was performed on Day 32. Nonpregnant control cows (n = 102) were resynchronized immediately using Ovsynch-56, and control heifers (n = 76) were resynchronized using 5-day Cosynch starting on Day 34 therefore, cows and heifers were reinseminated on Day 42. Nonpregnant 21dRES animals that had not been reinseminated on Day 21 were resynchronized concurrently with the control animals. Pregnancy per AI (PAI) for the initial TAI was similar (P = 0.80) for 21dRES and control cows (30.3% vs. 29.4%) and heifers (49.4% vs. 51.3%). Of the nonpregnant 21dRES animals, 33 of 76 cows (43.4%) and 22 of 39 heifers (56.4%) had been reinseminated on Day 21. Therefore, the RI was decreased by 9.9 days (33.3 ± 1.0 vs. 43.2 ± 1.0 days P < 0.001) in 21dRES cows and by 12.2 days in 21dRES heifers (30.1 ± 1.3 vs. 42.3 ± 1.3 days P < 0.001) compared with controls. The overall resynchronized PAI was similar for 21dRES cows compared with controls (31.6% vs. 25.0% P = 0.23). The PAI was 24.2% for 21dRES cows reinseminated on Day 21 and 37.2% for 21dRES cows reinseminated on Day 42. The overall resynchronized PAI was increased for 21dRES heifers compared with controls (57.5% vs. 32.4% P = 0.03) because 21dRES heifers reinseminated on Day 21 had similar PAI compared with controls (43.5% vs. 32.4% P = 0.39), but PAI was increased for 21dRES heifers reinseminated on Day 42 compared with controls (76.5% vs. 32.4% P = 0.003). Consequently, the proportion of animals pregnant from the initial and resynchronized TAI tended to be increased in 21dRES heifers (79.0% vs. 67.1% P = 0.09). Cost per pregnancy was decreased for the 21dRES in heifers. In conclusion, 21dRES provided a useful method to decrease the RI in cows and heifers, and to increase PAI and decrease cost per pregnancy in heifers.
Publisher: American Dairy Science Association
Date: 02-2014
Abstract: The objectives were to study the effects of induced subclinical hypocalcemia [SCH, blood ionized Ca (iCa(2+)) <1.0mM, without recumbency] on physiological responses and function of immune cells in dairy cows. Ten nonpregnant, nonlactating Holstein cows were blocked by lactation and assigned randomly to a normocalcemic (NC intravenous infusion of 0.9% NaCl i.v. plus 43 g of oral Ca, as Ca sulfate and Ca chloride, at -1 and 11h) or an induced SCH [SCHI, 5% ethylene glycol tetraacetic acid (EGTA), a selective iCa(2+) chelator, intravenous infusion] treatment for 24h, using a crossover design. The sequence of treatments was either NC-SCHI or SCHI-NC, with a 6-d washout period. Ionized Ca was evaluated before, hourly during the infusion period, and at 48 and 72 h, to monitor concentrations and adjust the rate of infusion, maintaining blood iCa(2+) <1.0mM in SCHI throughout the 24-h infusion period. Additional measurements included heart and respiratory rates, rectal temperature, dry matter intake, rumen contractions, whole-blood pH, concentrations of glucose and K in whole blood, concentrations of total Ca, Mg, nonesterified fatty acids, β-hydroxybutyrate, and insulin in plasma, and urinary excretion of Ca. Total and differential leukocyte count in blood was also performed. The concentration of cytosolic iCa(2+) in neutrophils and lymphocytes was quantified and neutrophil function was assayed in vitro. Infusion of a 5% EGTA solution successfully induced SCH in all SCHI cows, resulting in decreased blood iCa(2+) concentrations throughout the 24-h treatment period (0.77 ± 0.01 vs. 1.26 ± 0.01 mM iCa(2+)). Induction of SCH reduced dry matter intake on the day of infusion (5.3 ± 0.8 vs. 9.1 ± 0.8 kg/d) and rumen contractions (1.9 ± 0.2 vs. 2.7 ± 0.2 contractions/2 min) for the last 12h of infusion. Cows in SCHI had decreased plasma insulin concentration (1.44 ± 0.23 vs. 2.32 ± 0.23 ng/mL) evident between 6 and 18 h after the beginning of the infusion, accompanied by increased concentrations of glucose (4.40 ± 0.04 vs. 4.17 ± 0.04 mM). Plasma nonesterified fatty acids concentration was greater for SCHI than NC cows (0.110 ± 0.019 vs. 0.061 ± 0.014 mM). Neutrophils of cows in SCHI had a faster decrease in cytosolic iCa(2+) after stimulation with ionomycin (9.9 ± 1.0 vs. 13.6 ± 1.4 Fluo-4:Fura Red post-end ratio) in vitro. Furthermore, induction of SCH reduced the percentage of neutrophils undergoing phagocytosis (22.1 ± 2.1 vs. 29.3 ± 2.1%) and reduced the oxidative burst response after incubation of pathogenic bacteria (16.1 ± 1.7 vs. 24.2 ± 1.7%). Subclinical hypocalcemia compromised appetite, altered metabolism, and impaired function of immune cells in dairy cows.
Publisher: American Dairy Science Association
Date: 2003
Publisher: Editora Scienza
Date: 04-12-2019
Publisher: American Dairy Science Association
Date: 08-2014
Abstract: The aim of this study was to compare the reproductive performance of dairy cows subjected to early (ER) or late (LR) resynchronization programs after nonpregnancy diagnoses based on either pregnancy-associated glycoproteins (PAG) ELISA or transrectal palpation, respectively. In addition, the accuracy of the PAG ELISA for early pregnancy diagnosis was assessed. Lactating Holstein cows were subjected to a Presynch-Ovsynch protocol with timed artificial insemination (AI) performed between 61 and 74 DIM. On the day of the first postpartum AI, 1,093 cows were blocked by parity and assigned randomly to treatments however, because of attrition, 452 ER and 520 LR cows were considered for the statistical analyses. After the first postpartum AI, cows were observed daily for signs of estrus and inseminated on the same day of detected estrus. Cows from ER that were not reinseminated in estrus received the first GnRH injection of the Ovsynch protocol for resynchronization 2d before pregnancy diagnosis. On d 28 after the previous AI (d 27 to 34), pregnancy status was determined by PAG ELISA, and nonpregnant cows continued on the Ovsynch protocol for reinsemination. Pregnant cows had pregnancy status reconfirmed on d 46 after AI (d 35 to 52) by transrectal palpation, and those that lost the pregnancies were resynchronized. Cows assigned to LR had pregnancy diagnosed by transrectal palpation on d 46 after AI (d 35 to 52) and nonpregnant cows were resynchronized with the Ovsynch protocol. Blood was s led on d 28 after AI (d 27 to 34) from cows in both treatments that had not been reinseminated on estrus and again on d 46 after AI (d 35 to 52) for assessment of PAG ELISA to determine the accuracy of the test. Cows were subjected to treatments for 72d after the first insemination. Pregnancy per AI (P/AI) at first postpartum timed AI did not differ between treatments and averaged 28.9%. The proportion of nonpregnant cows that were resynchronized and received timed AI was greater for ER than for LR (30.0 vs. 7.6%). Cows in ER had a shorter interval between inseminations when inseminated following spontaneous estrus (21.7±1.1 vs. 27.8±0.8d) or after timed AI (35.3±1.2 vs. 55.2±1.4d). Nevertheless, the ER did not affect the rate of pregnancy (adjusted hazard ratio=1.23 95% confidence interval=0.94 to 1.61) or the median days postpartum to pregnancy (ER=132 vs. LR=140). A total of 2,129 PAG ELISA were evaluated. Overall, sensitivity, specificity, and positive and negative predictive values averaged 95.1, 89.0, 90.1, and 94.5%, respectively, and the accuracy was 92.1%. In conclusion, PAG ELISA for early diagnosis of pregnancy had acceptable accuracy, but early resynchronization after nonpregnancy diagnosis with PAG ELISA did not improve the rate of pregnancy or reduce days open in dairy cows continuously observed for estrus.
Publisher: American Dairy Science Association
Date: 2016
Publisher: Editora Scienza
Date: 11-11-2019
Publisher: American Dairy Science Association
Date: 12-2017
Abstract: The objectives were to investigate the effects that maternal diets containing negative dietary cation-anion differences (DCAD) fed in the last 42 d of gestation may have on the acid-base status, hematology, mineral and energy metabolism, growth, and health of calves. The experiment was a randomized block design with a 2 × 2 factorial arrangement of 2 levels of negative DCAD (-70 or -180 mEq/kg) and 2 feeding durations (the last 21 d prepartum and the last 42 d prepartum). Bulls and heifers (n = 60) born to these dams were weighted at birth and fed 3.8 L of colostrum for their first feeding, and only heifers (n = 44, 9-12/treatment) were kept thereafter. Heifer body weight was also recorded at 21 d, 42 d, 62 d, 3 mo, and 6 mo of age. Blood was collected at birth, before colostrum feeding, and at 1, 2, 3, 21, and 42 d of age and assayed for minerals, metabolites, and cell counts. Heifers born to dams fed the last 42 d prepartum weighed 2.8 and 4.8 kg less at birth and 62 d, respectively, compared with calves born to dams fed the last 21 d prepartum however, body weight at 3 and 6 mo of age was similar. Concentrations of ionized calcium did not differ among treatments at birth, but heifers born to -180 DCAD dams had increased blood concentrations at 3 d of age, whereas those born to -70 DCAD dams did not. At birth, heifers born to -180 DCAD dams experienced a subtle and transient metabolic acidosis (pH = 7.33 ± 0.02 pCO
Publisher: Elsevier BV
Date: 2004
DOI: 10.1016/S0093-691X(03)00242-5
Abstract: This study examined the influence of a GnRH agonist containing either 450 or 750 microg of deslorelin in an implant form or a gonadorelin injection (control) to induce ovulation in the Ovsynch protocol on pregnancy rates (PR), embryonic loss, and ovarian function in 593 lactating Holstein cows. Cows were given two injections of PGF2alpha 14 days apart, followed 14 days later by the Ovsynch protocol, and were timed artificially inseminated (TAI) at 68 +/- 3 days postpartum. Blood s les for determination of plasma progesterone concentrations were collected at 24 and 10 days prior to and 11 days after TAI. Pregnancy was diagnosed on Day 27 and reconfirmed on Day 41 after TAI. Non-pregnant, not re-inseminated cows at Day 27 had their ovaries examined by ultrasonography, and the number and size of follicles and presence of luteal tissue were determined. Simultaneously, these cows were re-synchronized with the Ovsynch protocol. Pregnancy during the re-synchronization period was determined between 35 and 41 days after insemination. On Day 27, PR were higher for control (39.0%) and deslorelin 450 microg (DESLORELIN 450) implant (41.3%) than for those receiving the deslorelin 750 microg (DESLORELIN 750) implant (27.5% P<0.05). Pregnancy losses tended to decrease for DESLORELIN 450 compared with control (5.0% versus 12.7% P<0.13). Plasma progesterone concentrations did not differ significantly among treatments. Deslorelin suppressed ovarian activity and decreased PR during the re-synchronization period compared with control. The percentage of non-pregnant animals that were re-inseminated by Day 27 was less for deslorelin compared with control. In conclusion, incorporation of an implant of the GnRH agonist deslorelin to induce ovulation in the Ovsynch protocol has the potential to reduce pregnancy losses, but the response was dependent upon implant concentration. Evaluation of lower doses to minimize the negative effects on subsequent fertility is warranted.
Publisher: American Dairy Science Association
Date: 09-2013
Abstract: The objectives were to characterize the prevalence of periparturient diseases and their effects on reproductive performance of dairy cows in seasonal grazing farms. A total of 957 multiparous cows in 2 farms (555 in farm A and 402 in farm B) were evaluated and diseases characterized. At calving, dystocia, twin birth, stillbirth, and retained fetal membranes were recorded and grouped as calving problems. On d 7±3 and 14±3 postpartum, cows were evaluated for metritis and on d 28±3 for clinical endometritis based on scoring of the vaginal discharge. From parturition to 30 d after artificial insemination (AI), prevalence of mastitis, lameness, and digestive and respiratory problems were recorded. For subclinical diseases, diagnosis was based on blood s les collected from 771 cows and analyzed for concentrations of Ca, nonesterified fatty acids (NEFA), and β-hydroxybutyrate. Cows were considered as having elevated NEFA concentration if the concentration was ≥0.70 mM, subclinical ketosis if the β-hydroxybutyrate concentration was ≥0.96 mM, and subclinical hypocalcemia if the Ca concentration was ≤2.14 mM. Ovaries were scanned on d 35±3 and 49±3 postpartum for determination of estrous cyclicity. All cows were enrolled in a timed AI program and inseminated on the first day of the breeding season: on average, 86 d postpartum. Overall, 37.5% (359/957) of the cows presented at least 1 clinical disease and 59.0% (455/771) had at least 1 subclinical health problem. Prevalence of in idual diseases was 8.5% for calving problems, 5.3% for metritis, 15.0% for clinical endometritis, 13.4% for subclinical endometritis, 15.3% for mastitis, 2.5% for respiratory problems, 4.0% for digestive problems, 3.2% for lameness, 20.0% for elevated NEFA concentration, 35.4% for subclinical ketosis, and 43.3% for subclinical hypocalcemia. Clinical and subclinical diseases had additive negative effects on reproduction, delaying resumption of estrous cyclicity and reducing pregnancy per AI (P/AI). Occurrence of multiple diseases further reduced reproductive efficiency compared with a single disease. In idually, subclinical hypocalcemia, elevated NEFA concentration, metritis, and respiratory and digestive problems reduced estrous cyclicity by d 49 postpartum. Elevated NEFA concentration, calving problem, metritis, clinical and subclinical endometritis, and digestive problems reduced P/AI on d 65 after AI. Moreover, calving problems and clinical endometritis increased the risk of pregnancy loss between gestation d 30 and 65. Serum concentrations of Ca and NEFA were negatively correlated, and both were associated with prevalence of uterine diseases. In conclusion, periparturient diseases were highly prevalent in seasonally calving grazing dairies and affected cows had delayed resumption of estrous cyclicity, reduced P/AI, and increased risk of pregnancy loss.
Publisher: American Dairy Science Association
Date: 2014
Abstract: The objectives were to evaluate the effect of supplementing saturated or unsaturated long-chain fatty acids (FA) to nulliparous and parous Holstein animals (n=78) during late gestation on FA profile of colostrum and plasma of newborn calves and on production and absorption of IgG. The saturated FA supplement (SAT) was enriched in C18:0 and the unsaturated FA supplement (ESS) was enriched in the essential FA C18:2n-6. Fatty acids were supplemented at 1.7% of dietary dry matter to low-FA diets (1.9% of dietary dry matter) during the last 8 wk of gestation. Calves were fed 4 L of colostrum within 2h of birth from their own dam or from a dam fed the same treatment. Feeding fat did not affect prepartum dry matter intake, body weight change, or gestation length. Parous but not nulliparous dams tended to give birth to heavier calves if fed fat prepartum. Parous dams were less able to synthesize essential FA derivatives, as evidenced by lower desaturase indices, compared with nulliparous dams, suggesting a greater need for essential FA supplementation. The FA profile of colostrum was modified to a greater degree by prepartum fat feeding than was that of neonatal calf plasma. The placental transfer and synthesis of elongated n-3 FA (C20:5, C22:5, and C22:6) were reduced, whereas the n-6 FA (C18:2, C18:3, and C20:3) were increased in plasma of calves born from dams fed ESS rather than SAT. Supplementing unsaturated FA prepartum resulted in elevated concentrations of trans isomers of unsaturated monoene and diene FA, as well as C18:2n-6 in colostrum. Serum concentrations of IgG tended to be increased in calves born from dams fed fat compared with those not fed fat, and prepartum feeding of SAT tended to improve circulating concentrations of IgG in newborn calves above the feeding of ESS. Apparent efficiency of absorption of IgG was improved in calves born from dams fed fat, and SAT supplementation appeared more effective than supplementation with ESS. Feeding SAT prepartum may be of greater benefit based upon greater circulating IgG concentrations of calves after colostrum feeding. Feeding moderate amounts of saturated or unsaturated long-chain FA during the last 8 wk of gestation changed the FA profile of colostrum and plasma of neonates to reflect that of the supplements.
Publisher: American Dairy Science Association
Date: 2002
DOI: 10.3168/JDS.S0022-0302(02)74064-2
Abstract: Objectives were to determine net release or uptake of a-amino N, ammonia N, and urea N across portal-drained viscera, liver, splanchnic, and mammary tissues of lactating Holstein cows (n = 6 109 +/- 9 d in milk) fed alfalfa hay-based total mixed rations (TMR) containing 40% steam-rolled or steam-flaked corn grain. The TMR were offered at 12-h intervals in a crossover design. Blood s les were obtained from indwelling catheters in portal, hepatic, and mammary veins and mesenteric or costo abdominal arteries, every 2 h for each cow and diet. Steam-flaked compared with steam-rolled corn greatly increased in vitro starch hydrolysis (56 vs. 34%). Daily intake of dry matter (18.4 +/- 0.4 kg/d), starch, N, and net energy for lactation by cows were not altered by processing corn neither were daily yield of milk (29.1 +/- 0.7 kg/d), fat-corrected milk, nor fat-corrected milk per dry matter intake. Steam-flaking tended to increase percent milk protein (2.97 vs. 2.82% P = 0.07), but not yield, and decrease percent lactose (4.83 vs. 4.94) but not yield. Portal and hepatic blood flows were not affected by diet, nor were net absorption of alpha-amino N and ammonia N. Steam-flaking compared with steam-rolling increased urea N cycling to portal-drained viscera (212 vs. 87 g/d) by 140%, estimated mammary uptake and extraction ratio of alpha-amino N. Flaking versus rolling of corn improved N utilization in dairy cows by increasing urea cycling to the gut and uptake of a-amino N by the mammary gland. Higher mammary uptake of alpha-amino N (78 vs. 50 g/d) by dairy cows fed steam-flaked corn tended to increase milk protein content and may explain the previously observed effects of cows fed steam-flaked versus steam-rolled corn.
Publisher: American Dairy Science Association
Date: 08-2008
Abstract: Our objectives were to determine the effects of dietary free gossypol (FG) intake on plasma and uterine gossypol concentrations and embryo development and viability before and after culture with gossypol. Fifty postpubertal Holstein heifers weighing (+/-SD) 406 +/- 34.5 kg at 11.5 mo of age were blocked by age and body weight (BW) and randomly assigned to 1 of 3 isocaloric and isonitrogenous diets differing in their FG content: control (0 mg of FG/kg of BW), moderate (17.8 mg of FG/ kg of BW), and high (36.8 mg of FG/kg of BW). Heifers were fed the diets for 70 d before superovulation and embryo collection. Superovulated heifers were flushed on d 5 after induction of ovulation, and early morulae were either stained, to determine the number and proportion of live and dead cells, or randomly assigned to an in vitro culture for 96 h in media containing either 0 or 10 mug/mL of gossypol acetic acid. Plasma and uterine gossypol concentrations increased with increasing gossypol intake. The number of low-quality embryos-ova was greater for the high than for the moderate and control diets. Embryos collected from the high diet had the least number of cells because of fewer live cells, and were smaller in diameter. Greater dietary gossypol reduced blastocyst development and extended the time to reach the blastocyst stage. Similarly, gossypol concentration at 10 microg/mL compromised in vitro development and increased the proportion of degenerated embryos at 96 h in culture. These findings provide in vivo and in vitro evidence that intake of 36.8 mg of FG/kg of BW per d and gossypol concentrations >7 microg/mL in plasma, in uterine flush, or in vitro compromise early embryo development, which might explain some of the negative effects of gossypol on the fertility of dairy cows.
Publisher: American Dairy Science Association
Date: 10-2001
Publisher: Elsevier BV
Date: 09-2004
Publisher: American Dairy Science Association
Date: 12-2019
Abstract: The objective of this study was to evaluate expression of a cluster of genes encoding β-defensin antimicrobial peptides in neutrophils of postpartum cows in relation to prepartum dietary cation-anion difference (DCAD), vitamin D, and postpartum disease. Pregnant dry Holstein cows (28 nulliparous and 51 parous) at 255 d gestation were blocked by parity and randomly assigned to 4 prepartum diets of positive (+130 mEq/kg) or negative (-130 mEq/kg) DCAD and either 3 mg vitamin D
Publisher: American Dairy Science Association
Date: 08-2013
Abstract: The objectives of this study were to evaluate 2 feeding strategies for early lactation cows on performance and efficiency of nutrient utilization. Fifty-eight Holsteins cows were blocked by parity and production during the pretreatment period and then randomly assigned at 21 d postpartum to a control diet [n=29 16.2% crude protein, 1.64 Mcal of net energy for lactation (NE(L)), 22% starch, and 19% forage neutral detergent fiber (NDF)] or a diet with caloric density manipulated weekly (precision diet n=29 16.2% crude protein 1.59 to 1.68 NE(L) 18 to 26% starch and 16 to 22% forage NDF) to promote a calculated positive energy balance of 5 Mcal/day. Diets were fed as total mixed rations and precision cows had their diets adjusted in idually once a week, by feeding additional grain supplementation from 0 to 25% of daily dry matter (DM) offered, according to the energy balance of the preceding week. Energy balance was calculated daily and then averaged weekly. The study lasted from wk 3 to 19 postpartum, and nutrient digestibility, rumen fluid composition, urinary output, estimates of microbial protein synthesis, and feeding behavior were evaluated between wk 9 and 13 postpartum. Compared with controls, precision cows had similar DM intake (24.3 kg/d), but NE(L) intake tended to be greater primarily between wk 4 and 8 postpartum. Yields of milk (45.2 vs. 41.9 kg/d), milk components, 3.5% fat-corrected milk (44.0 vs. 40.8 kg/d), and energy-corrected milk (43.4 vs. 40.2) were all greater for precision than control cows, resulting in greater energy-corrected milk production per kilogram of diet DM consumed (1.79 vs. 1.72). Precision cows produced more milk calories per kilogram of metabolic weight (0.227 vs. 0.213 Mcal of NE(L)/kg), although the amount of consumed calories partitioned into milk (82.3%) and measures of energy status did not differ between treatments throughout the study. Glucose concentrations were greater throughout the day in precision cows compared with controls at 6 wk, but not 13 wk postpartum. Apparent digestibility of nutrients, composition of rumen fluid, mean and low rumen pH, and estimated rumen microbial N synthesis remained mostly unaltered by treatments. Although precision cows produced more milk true protein, measures of efficiency of dietary N use were not influenced by treatment. On wk 13 postpartum, precision cows consumed a diet with longer NDF particles, which resulted in a tendency for greater intake of NDF >8mm because of less sorting against the long particles than control cows. Meal pattern differed with treatment, and precision cows consumed feed more sparsely throughout the day, spent more time ruminating lying, and had similar meal duration (mean of 36.3 min/meal) compared with control cows, but smaller meal size (3.33 vs. 3.64 kg/meal). Results from the current study indicate that allocating dietary resources according to the in idual needs of cows based on energy balance improves lactation performance compared with feeding a single total mixed ration, despite similar average nutrient intake between treatments. Improvements in performance are likely related to allocation of calories based on the needs of the cow and on shifts of feeding behavior that might favor intake of smaller meals.
Publisher: American Dairy Science Association
Date: 11-2018
Abstract: Objectives were to evaluate the effects of altering the dietary ratio of omega-6 (n-6) to omega-3 (n-3) fatty acids on the profile of fatty acids and expression of genes related to the prostaglandin biosynthesis on endometrial tissue, uterine secretion of PGF
Publisher: American Dairy Science Association
Date: 05-2021
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.THERIOGENOLOGY.2014.09.021
Abstract: The objectives of this study were to determine the effects of supplemental progesterone on fertility responses of lactating dairy cows with a CL at the initiation of the timed artificial insemination (AI) program. Holstein cows were subjected to the Ovsynch protocol (Day -10 GnRH, Day -3 PGF2α, Day -0.7 GnRH, and Day 0 timed AI). Ovaries were scanned by ultrasonography on Day -10 and cows with CL were blocked by pen and assigned randomly to receive no supplemental progesterone (control, n = 863) or to receive a controlled internal drug-release (CIDR) insert containing progesterone from Days -10 to -3 (1CIDR, n = 862). Cows were observed for signs of estrus beginning on Day -9 based on removal of tail chalk and those in estrus received AI on the same day. Blood s led from a subset of cows was analyzed for progesterone concentrations on Days -10, -9, -7, -5, -3, 0, 6, 13, and 19. Pregnancy was diagnosed on Days 32 and 60 after AI. Supplementation increased (P < 0.01) progesterone concentrations between Day -9 and -3 compared with control (7.5 vs. 6.2 ng/mL). Treatment had no effect on the ovulatory response to the first and final GnRH injections of the Ovsynch protocol, the proportion of cows that maintained their CL until the day of PGF2α injection, or the diameter of the ovulatory follicle before AI. Although the overall proportion of cows in estrus at AI did not differ between treatments, progesterone supplementation prevented (P < 0.01) cows from coming into estrus from Days -9 to -3 (0.0% vs. 4.7%), whereas it increased (P = 0.02) the proportion of cows inseminated in estrus from Days -2 to -1 (7.1% vs. 4.5%). Pregnancy per AI (P/AI) tended to be reduced (P = 0.06) by supplemental progesterone on Day 32 (40.5% vs. 45.0%), but not on Day 60 after AI (36.6% vs. 39.7%). A tendency for an interaction (P = 0.09) between treatment and the presence of CL at the PGF2α injection was observed for P/AI on Day 32 in cows that received timed AI because progesterone supplementation reduced P/AI in cows that maintained their CL until Day -3 (40.3% vs. 46.7%) however, it increased P/AI in those that did not have a CL at PGF2α (38.1% vs. 27.7%). Treatment did not affect pregnancy loss between Days 32 and 60 of gestation. In conclusion, incorporating a single intravaginal insert to the timed AI program increased progesterone concentrations in plasma by 1.3 ng/mL, but did not benefit fertility in dairy cows that have CL at the initiation of the synchronization protocol.
Publisher: American Dairy Science Association
Date: 03-2003
Publisher: American Dairy Science Association
Date: 02-1999
Publisher: University of Toronto Press Inc. (UTPress)
Date: 06-2004
Abstract: There are four different levels of continuing education program evaluation: participant perceptions of the program or course participant competence with new skills, knowledge, and abilities participant performance or change in behavior and health care or client outcomes, such as resultant changes in patient care or herd/flock production performance. The purpose of this article is to describe different levels of evaluation and demonstrate some methods used in evaluating a continuing veterinary medical education (CVME) course in dairy reproductive management. Participants’ learning needs were assessed using learning stage theory and a pre-test of knowledge. Post-program assessments included a test of knowledge, a satisfaction survey, a commitment to change, and self-reported behavior change. The results of the evaluation indicate that self-reports of learning needs do not necessarily reflect actual needs and that satisfaction with a course does not necessarily indicate behavior change. Providers of CVME must recognize the value of program evaluation, as well as the advantages and disadvantages of different evaluation methods.
Publisher: American Dairy Science Association
Date: 03-2019
Abstract: Prepartum diets influence cow performance for weeks to months postpartum. This observation leads to questions about milk yield and physiological and health responses to diets with negative dietary cation-anion difference (DCAD). Further, responses to increased intake of a diet with lower DCAD (Eq/d) have not been explored using meta-analysis. Our objectives were to explore the effects of prepartum DCAD intake on metabolism and production and health as well as the potential for differences in intake of other macrominerals to influence responses to differences in DCAD intake using classical meta-analytical methods. Not all treated groups were fed a diet with negative DCAD, and the effect studied is that of reducing the DCAD. We hypothesized that reducing DCAD intake would improve Ca metabolism and postpartum performance. We used a maximum of 58 comparisons from 31 experiments and a total of 1,571 cows. Intakes of DCAD were 2.28 Eq/d and -0.64 Eq/d for the control, higher DCAD and treated, lower DCAD groups, respectively. Diets with lower DCAD reduced urine pH [standardized mean difference (SMD) = 1.90 and weighted mean difference (WMD) -1.23 pH]. Intake of lower DCAD decreased prepartum DMI (SMD = 0.23 WMD = 0.29 kg/d), increased postpartum DMI (SMD = 0.40 WMD = 0.63 kg/d), and increased milk yield (SMD = 0.172). However, we found an interaction with parity diets with lower DCAD increased milk yield in parous cows (SMD = 0.29 WMD = 1.1 kg/d) but resulted in numerically lower milk yield in nulliparous cows (SMD = -0.20 WMD = 1.28 kg/d) compared with controls. The FCM yield increased with treatment (SMD = 0.12 WMD = 0.56 kg/d) however, yield of treated cows tended to be greater in parous cows but smaller for nulliparous cows compared with controls. Milk fat percentage, milk fat yield, and milk protein percentages were not affected by treatment, although milk protein yield tended to increase in cows fed the lower DCAD diet (SMD = 0.21 WMD = 0.02 kg/d). Treatment increased blood Ca (SMD = 0.53 WMD = 0.13 mM) and P (SMD = 0.40 WMD = 0.13 mM) on the day of calving and Ca postpartum (SMD = 0.36 WMD = 0.06 mM). Treated cows had smaller concentration of blood BHB before calving than controls (SMD = -0.39 WMD = -0.04 mM). Reducing DCAD in cows resulted in decreased risks of clinical hypocalcemia (risk ratio = 0.60) and retained placenta (risk ratio = 0.59), and reduced the odds of metritis (odds ratio = 0.46) and overall disease (OR = 0.61). We observed no effect on risk of abomasal displacement or mastitis and no effect of differences between treated and control cows in Ca intake (g/d) on the outcomes evaluated. A positive role for increased Mg intake between groups for increased milk fat yield and in reducing the risk of retained placenta was identified. Diets with lower DCAD improved performance of parous dairy cows, and our findings suggest a need for more studies on the effects of a lower DCAD on nulliparous transition cows.
Publisher: American Dairy Science Association
Date: 2021
Publisher: Wiley
Date: 30-10-2019
DOI: 10.1002/MRD.23288
Publisher: American Dairy Science Association
Date: 11-2016
Abstract: The objectives were to evaluate the clinical response to intrauterine administration of chitosan microparticles (CM) and to assess efficacy for preventing metritis in dairy cows. Holstein cows (n=104 40 primiparous and 64 multiparous) at increased risk for metritis (cows that had abortion, dystocia, twins, stillbirth, or retained placenta) were randomly assigned to 1 of 2 treatments at 1d in milk (DIM 24h postpartum): CM group (n=52), daily intrauterine infusion of 8g of CM dissolved in 40mL of sterile water for 5d control (CON) group (n=52), daily intrauterine infusion of 40mL of sterile water for 5d. Clinical response was assessed by evaluation of parameters associated with inflammation (rectal temperature and plasma haptoglobin concentration) and metabolism [plasma nonesterified fatty acid (NEFA) and β-hydroxybutyrate (BHB) concentrations] up to 14 DIM, and daily milk yield up to 30 DIM. Uterine discharge pH was evaluated at 4, 7, 10, and 14 DIM as an indicator of bacterial load and acid byproduct production. The cumulative incidence of metritis was evaluated up to 4, 7, 10, and 14 DIM. Continuous and dichotomous outcomes were evaluated with mixed linear and logistic regression analysis, respectively. Treatment with CM did not affect rectal temperature (39.17±0.04 vs. 39.14±0.04°C), haptoglobin (1.10±0.05 vs. 1.07±0.05mg/mL), NEFA (0.64±0.04 vs. 0.63±0.04mmol/L), BHB (0.61±0.03 vs. 0.57±0.03mmol/L), or milk yield (30.3±0.92 vs. 30.1±0.97kg/d) compared with CON. An interaction between treatment and time showed that NEFA concentrations were lower for CM than CON at 10 DIM (0.46±0.06 vs. 0.64±0.06mmol/L). Treatment with CM resulted in greater uterine discharge pH than CON (6.91±0.03 vs. 6.83±0.02). Cows that developed metritis had increased concentrations of haptoglobin and BHB, and decreased uterine discharge pH and milk yield. Treatment with CM resulted in decreased incidence of metritis up to 7 DIM compared with CON (46.2 vs. 65.4%) however, no differences were found at 4 (11.5 vs. 17.3%), 10 (61.5 vs. 73.1%), and 14 DIM (63.5 vs. 73.1%) for CM versus CON, respectively. In conclusion, CM did not alter clinical parameters of cows at risk for metritis, and may merit further investigation for prevention of metritis. However, the duration of treatment may have to be extended to effectively reduce the incidence of metritis during the high-risk period.
Publisher: Elsevier BV
Date: 2006
DOI: 10.1016/J.THERIOGENOLOGY.2005.10.004
Abstract: The high producing dairy cow of the 21st century is subfertile during lactation. Our objectives are to characterize physiological periods limiting reproductive performance and to describe integrated management strategies to improve pregnancy rates. Ovarian recrudescence with normal re-occurring estrous cycles and restoration of fertility to first service are associated with a reduced occurrence of periparturient metabolic and reproductive disorders. Marked negative changes in energy balance and reduced immunocompetence influence gonadotropic and metabolic hormones. Induced ovarian inactivity was associated with enhanced uterine involution. Post-partum health and reproductive performance were improved when by-pass lipids enriched in polyunsaturated fatty acids were fed in the pre- and post-partum periods. Pharmaceutical control of follicle, CL, and uterine function with PGF, GnRH and intravaginal progesterone releasing inserts, has permitted development of more optimal timed-insemination programs for first service. Likewise, resynchronization of nonpregnant cows coupled with the use of ultrasound for early pregnancy diagnosis provides the opportunity for a second timed-insemination within 3 days of a nonpregnant diagnosis. Bovine somatotropin (bST) increases embryo development and embryo survival when coupled with a timed-insemination program or cows detected in estrus. Presence of a conceptus alters endometrial expression of genes and proteins in response to bST and nutraceuticals (i.e., unsaturated fatty acids such as eicosapentaenoic and docosahexaenoic acid in by-pass lipids) to improve pregnancy rates. Postovulatory increases in progesterone may enhance pregnancy rates in targeted populations of lactating dairy cows, but timing and magnitude of the progesterone increases are pharmaceutically dependent.
Publisher: American Dairy Science Association
Date: 05-2000
Publisher: American Dairy Science Association
Date: 10-2011
Abstract: The objective of this observational field study was to validate the relationship of serum concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and calcium with disease in early lactation across different management systems. Fifty-five Holstein freestall dairy herds located across the United States and Canada were selected and visited weekly for blood s le collection from 2,365 cows. Only diseases that were consistently recorded across herds and blood s les collected before the disease occurred were considered. Metabolite concentrations in serum in wk -1 relative to calving were considered as predictors of retained placenta (RP) and metritis, and metabolite concentrations in serum in wk -1 and wk +1 relative to calving were considered as predictors of displaced abomasum (DA). For each disease, each metabolite, and week of s ling in the case of DA, a critical threshold was calculated based on the highest combined sensitivity and specificity and used to categorize the serum concentrations into high and low risk categories. Multivariable logistic regression models were built for each disease of interest and week of s ling, considering cow as the experimental unit and herd as a random effect. Cows with precalving serum NEFA concentrations ≥ 0.3 mEq/L were more likely to develop RP [odds ratio (OR) = 1.8 95% confidence interval (CI) = 1.3 to 2.6] and metritis (OR = 1.8 95% CI = 1.5 to 2.9) after calving than cows with lower NEFA concentrations. Precalving NEFA ≥ 0.5 mEq/L (OR = 2.4 95% CI = 1.5 to 3.7), postcalving NEFA ≥ 1.0 mEq/L (OR = 2.7 95% CI = 1.7 to 4.4), and postcalving calcium ≤ 2.2 mmol/L (OR = 3.1 95% CI = 1.9 to 5.0) were associated with subsequent risk of DA. In conclusion, elevated serum NEFA concentrations within 1 wk before calving were associated with increased risk of RP, metritis, and DA after calving. Serum NEFA and calcium concentrations in the 2 wk around calving in combination were associated with the risk of DA.
Publisher: American Dairy Science Association
Date: 12-2021
Publisher: American Dairy Science Association
Date: 11-2019
Abstract: The objectives were to review the published literature and use meta-analytic methods to determine the effects of dietary protein fed prepartum on productive performance of dairy cows. The hypothesis was that responses to dietary protein prepartum would differ between nulliparous and parous cows, and performance would be maximized at a greater protein supply in nulliparous than in parous cows. The literature was systematically reviewed, searching randomized experiments in which the prepartum dietary content or degradability of protein was manipulated. Twenty-seven experiments including 125 treatment means and 1,801 cows were included in the meta-analysis. Of those, 8 experiments with 27 treatment means reported responses for 510 nulliparous cows. Data collected included the ingredient composition and chemical analyses of prepartum diets, parity group, and means and respective measures of variance for productive responses. Mixed model meta-analysis was conducted and statistical models investigated the effects of dietary crude protein (CP) or supply of metabolizable protein (MP) prepartum on performance. Supply of MP was predicted using the National Research Council Nutrient Requirements of Dairy Cattle (2001) model. The mean ± standard deviation and median (range) concentrations of dietary CP fed to cows prepartum were 14.4 ± 2.2 and 14.4% (8.9 to 20.9%), resulting in mean and median (range) intakes of CP prepartum of 1,720 ± 432 and 1,734 g/d (745 to 2,482 g/d). Predicted prepartum supply of MP averaged 822 ± 157 in nulliparous cows, ranging from 517 to 1,094 g/d, and 1,146 ± 316 in parous cows, ranging from 463 to 1,733 g/d. Increasing prepartum CP content or predicted supply of MP improved postpartum dry matter intake in nulliparous cows, but increasing prepartum CP content reduced prepartum dry matter intake in parous cows. Yields of milk and fat-corrected milk increased with increasing prepartum supply of MP in nulliparous but not in parous cows. Yields of fat and protein increased in nulliparous cows with increased CP content or supply of MP. Alternatively, in parous cows, yield of milk fat was not influenced by supply of MP but responded quadratically to dietary CP content and was maximized at approximately 14% CP. Dietary CP had no effect on protein yield in parous cows, but increasing the supply of MP improved protein yield only in cows from experiments with >36 kg/d of milk production, whereas MP supply had no effect on protein yield of parous cows from experiments with <28 kg/d of milk production. Performance of dairy cows was responsive to prepartum supply of MP and nulliparous benefited from diets with increased MP intake. Based on current results, production responses for nulliparous cows increased linearly up to the maximum MP intake of 1,100 g/d observed in the study, whereas for parous cows, only yield of milk protein in cows producing more than 36 kg of milk/d was influenced by supplying more than 800 g/d of MP.
Publisher: Oxford University Press (OUP)
Date: 12-2004
Abstract: The objectives of this study were to determine the effects of incorporating a progesterone intravaginal insert (CIDR) between the day of GnRH and PGF2alpha treatments of a timed AI protocol using estradiol cypionate (ECP) to synchronize ovulation on display of estrus, ovulation rate, pregnancy rate, and late embryonic loss in lactating cows. Holstein cows, 227 from Site 1 and 458 from Site 2, were presynchronized with two injections of PGF2alpha on study d 0 and 14, and subjected to a timed AI protocol (100 mixrog of GnRH on study d 28, 25 mg of PGF2alpha on study d 35, 1 mg of ECP on study d 36, and timed AI on study d 38) with or without a CIDR insert. Blood was collected on study d 14 and 28 for progesterone measurements to determine cyclicity. Ovaries were scanned on d 35, 37, and 42, and pregnancy diagnosed on d 65 and 79, which corresponded to 27 and 41 d after AI. Cows receiving a CIDR had similar rates of detected estrus (77.2 vs. 73.8%), ovulation (85.6 vs. 86.6%), and pregnancy at 27 (35.8 vs. 38.8%) and 41 d (29.3 vs. 32.3%) after AI, and late embryonic loss between 27 and 41 d after AI (18.3 vs. 16.8%) compared with control cows. The CIDR eliminated cows in estrus before the last PGF2alpha injection and decreased (P < 0.001) the proportion of cows bearing a corpus luteum (CL) at the last PGF2alpha injection because of less ovulation in response to the GnRH and greater spontaneous CL regression. Cyclic cows had greater (P = 0.03) pregnancy rates than anovulatory cows at 41 d after AI (33.8 vs. 20.4%) because of decreased (P = 0.06) late embryonic loss (16.0 vs. 30.3%). The ovulatory follicle was larger (P or = 15 mm displayed estrus (P < 0.001) and ovulated (P = 0.05) compared with cows with follicles <15 mm. Pregnancy rates were greater (P < 0.001) for cows displaying estrus, which were related to the greater (P < 0.001) ovulation rate and decreased (P = 0.08) late embryonic loss for cows in estrus at AI. Cows that were cyclic and responded to the presynchronization protocol (high progesterone at GnRH and CL at PGF2alpha) had the highest pregnancy rates. Incorporation of a CIDR insert into a presynchronized timed AI protocol using ECP to induce estrus and ovulation did not improve pregnancy rates in lactating dairy cows. Improvements in pregnancy rates in cows treated with ECP to induce ovulation in a timed AI protocol are expected when more cows display estrus, thereby increasing ovulation rate.
Publisher: Elsevier BV
Date: 2008
DOI: 10.1016/J.THERIOGENOLOGY.2007.09.010
Abstract: Nutrition of the donor cow can influence oocyte and embryo quality, which can affect the success of embryo transfer. Severe undernutrition compromised ovarian follicular development, with implications for superovulatory response and embryo quality. In postpartum lactating cows, undernutrition or inability to consume sufficient nutrients delayed resumption of ovulation, reduced the number of follicles, and compromised oocyte quality. Moderate undernutrition of nonlactating cows was unlikely to affect embryo quality conversely, nonlactating animals on maintenance diets usually had better superovulatory responses and improved oocyte competence and embryo quality. The negative effects of overfeeding are thought to be mediated by alterations in endocrine cues, such as hyperinsulinemia and increased glucose and IGF-I, which may interfere with glucose transport in the embryo and increase apoptosis. Manipulating energy sources such as carbohydrates and fatty acids (FA) may influence embryo viability, but the effects of FA were not consistent in vitro increasing concentrations of unsaturated FA in follicular and embryonic cells usually improved embryo viability and resistance to cryopreservation. Excess protein intake and increased urea and ammonia in body fluids can be toxic to embryos, impairing their development these effects seemed to be associated with alterations in uterine pH and granulosa cell function. Likewise, toxins in feeds (e.g. gossypol), reduced embryo development and increased pregnancy losses. Diet of donor cows should be formulated to optimize the supply of nutrients to meet needs however, manipulating energy intake, source of FA and protein content of donor diets, particularly moderate underfeeding in nonlactating cows, may further optimize responses.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.THERIOGENOLOGY.2015.07.004
Abstract: Objectives were to determine the effects of intrauterine infusion (IUI) of Trueperella pyogenes on endometrial expression of proinflammatory cytokines and luteal life span. Holstein cows (n = 32) were allocated randomly, in two replicates (15 then 17 cows), to receive one of three treatments on Day 5 of the estrous cycle: TP (n = 13), IUI containing 10(9) colony-forming units/mL of T. pyogenes tumor necrosis factor (TNF n = 9), IUI containing 1 μg of TNFα and control (n = 10), IUI of saline solution. Five cows per treatment had uterine biopsies collected at 6, 12, and 24 hours after treatment to evaluate the endometrial messenger RNA expression of TNFα (TNF), interleukin-1β (IL1B), IL6, IL8, prostaglandin E synthase (PGES), prostaglandin F synthase (PGFS), and oxytocin receptor (OXR), and histologic evidence of inflammation. Messenger RNA expression was measured using quantitative reverse transcription polymerase chain reaction. The remaining cows had ovaries scanned and blood collected for progesterone evaluation however, only seven, four, and three cows in the TP, TNF, and control groups were used for comparison in replicate 2. The GLIMMIX procedure of SAS was used for statistical analysis. All TP and TNF cows had moderate to severe endometrial inflammation, whereas only one control had mild inflammation. Premature luteolysis occurred in three, one, and zero cows in the TP, TNF and control groups, respectively. Delayed luteolysis occurred in one TP and one TNF cow. Interleukin-1β expression was greater in the TP cows than in the TNF cows at 24 hours after IUI. Moreover, IL6 expression tended to be greater for the TP cows than for the control cows at 12 hours after IUI. Interleukin 8 expression was greater in the TP cows than in the control and TNF cows at 24 hours after IUI. Oxytocin receptor expression tended to be greater for the TP cows and was greater for the TNF cows than for the control cows at 12 hours. The messenger RNA expressions of TNF, PGES, and PGFS were not affected by treatment, time, or their interaction. In conclusion, IUI of T. pyogenes or TNFα led to histologic evidence of inflammation and early luteolysis in some cows, which may have been caused by increased endometrial expression of proinflammatory cytokines (i.e., IL1B, IL6), chemokines (i.e., IL8), and luteolytic cascade factors (i.e., OXR).
Publisher: American Dairy Science Association
Date: 11-2014
Abstract: The objectives of this study were to identify factors associated with concentrations of anti-Müllerian hormone (AMH) in plasma of dairy cows and to investigate the relationships between plasma AMH and fertility responses during a 100-d breeding season. Lactating cows, 1,237 in 2 seasonally calving herds, had estrous cycles presynchronized and were enrolled in a timed artificial insemination (AI) protocol. All cows were inseminated on the first day of breeding season, considered study d 0. Blood was s led on d -8 and analyzed for concentrations of AMH and progesterone. From d 19 to 35, detection of estrus was performed daily and cows detected in estrus were reinseminated. On d 36, bulls were placed with cows for 65 d of natural service breeding. Factors identified to be associated with concentrations of AMH in plasma were breed of the cow and lactation number. Concentrations of AMH were greater for Jerseys, followed by crossbreds, and then Holsteins. Cows on lactations 2 and 3 had greater concentrations of AMH than those on lactations 1 and ≥ 4. Although pregnancy per AI at the timed AI was not associated with concentrations of AMH, cows with low AMH had greater detection of estrus at timed AI, and the latter benefited pregnancy per AI, particularly in cows that had low progesterone at the beginning of the synchronization protocol. Pregnancy loss between gestation d 30 and 65 was greater in cows with low AMH compared with those with intermediate or high AMH. Return to estrus in cows that failed to become pregnant from the timed AI was not associated with AMH, but pregnancy rate in cows bred on estrus (reinsemination + natural service) was associated positively with AMH. In conclusion, breed and lactation number were identified to be associated with concentrations of AMH in plasma. Concentration of AMH was associated positively with maintenance of pregnancy at the first postpartum AI and with pregnancy rate in cows inseminated after detection of spontaneous estrus. Synchronization of ovulation might override positive associations between AMH and fertility.
Publisher: American Dairy Science Association
Date: 06-2021
Publisher: American Dairy Science Association
Date: 06-2006
Publisher: Bioscientifica
Date: 05-2009
DOI: 10.1530/REP-08-0242
Abstract: Length of dominance of the ovulatory follicle and exposure to oestradiol (OE 2 ) during proestrus can affect fertility. Lactating cows had their oestrous cycle pre-synchronized and were subjected to one of the four synchronization treatments. Cows in the oestrus detection (OD) treatment received GnRH on day 6 of the oestrous cycle, PGF 2α 7 days later, and were inseminated at detected oestrus. The remaining cows were subjected to the Ovsynch (OVS) protocol (day 0 GnRH, day 7 PGF 2α , day 9 GnRH, and timed artificial insemination (AI) 12 h later) starting on day 3 (OVS3) or day 6 (OVS6 and OVS6E) of the oestrous cycle. Cows in the OVS6E treatment received an injection of 0.5 mg oestradiol cypionate 36 h before AI. Ovaries were examined by ultrasonography and blood was s led for progesterone and OE 2 concentrations. Uteri were flushed 6 days after AI and recovered embryos–oocytes evaluated. Diameter of the ovulatory follicle at AI differed ( P .01) among treatments, and it was the largest for OVS3 cows, which also had extended ( P .01) length of follicular dominance. During proestrus, OD and OVS6E cows had increased ( P .01) OE 2 concentrations. Fertilization was not altered by treatments, and maximum fertilization was achieved when the number of accessory spermatozoa was . Proportions of viable embryos in relation to embryos and embryos–oocytes recovered were smaller for OVS3 cows ( P .01) than the other treatments, and embryos from OVS3 cows also had fewer ( P .01) blastomeres and tended ( P =0.09) to have a lower proportion of live blastomeres. Extending the period of follicle dominance did not alter fertilization but reduced ( P .001) embryo quality. Embryo quality was compromised even when the dominance of the ovulatory follicle was extended by only 1.5 days.
Publisher: American Dairy Science Association
Date: 05-2012
Abstract: The objectives were to compare the effects of 2 methods of presynchronization and 2 lengths of proestrus on fertility of grazing dairy cows subjected to a 5-d timed artificial insemination (AI) protocol at initiation of breeding season. Lactating dairy cows (n=1,754) from 3 seasonal grazing farms were blocked within farm by breed, parity, and days in milk (DIM). Study d 0 was considered the day of AI of cows in COS72 (72h of proestrus). Within each block, cows were randomly assigned to 1 of 2 presynchronization treatments: a PGF(2α)-based program, Presynch, consisting of 2 injections of PGF(2α) administered on d -32 and -18, or a PGF(2α)-GnRH-based program, Double-Ovsynch (DO), consisting of GnRH on d -25, PGF(2α) on d -18, and GnRH on d -15. Within each of the 2 presynchronization treatments, cows were randomly assigned to 1 of 2 lengths of proestrus within the 5-d timed AI protocol, consisting of GnRH on d -8, PGF(2α) on d -3 and -2, and GnRH+AI at either 58 h (COS58) or 72 h (COS72) after the d -3 PGF(2α) injection. Ovaries were scanned by ultrasonography twice, on d -42 and -32, to determine estrous cyclicity before enrollment in the study. Blood was s led and analyzed for concentrations of estradiol on the day of AI. Pregnancies per AI (P/AI) were determined 30 and 65 d after AI. Presynchronization did not affect the concentration of estradiol at AI (DO=6.4 vs. Presynch=5.8 pg/mL), detection of estrus at AI (20.8 vs. 25.9%), or P/AI on d 30 (56.8 vs. 59.1%) and 65 (52.5 vs. 52.4%) after the first AI. Cows receiving COS72 had increased concentration of estradiol (6.6 vs. 5.5 pg/mL) and detection of estrus at AI (28.5 vs. 10.8%) compared with cows receiving COS58. Length of proestrus did not affect P/AI on d 30 (COS72=58.7 vs. COS58=56.1%) but, in Presynch cows, COS58 was detrimental to fertility on d 65 after AI (54.9 vs. 46.5%). Pregnancy loss between gestational d 30 and 65 was greater for Presynch than for DO (7.6 vs. 11.3%), but it was not affected by length of proestrus. Estrous cyclic cows had greater P/AI than anovular cows on d 30 (61.7 vs. 35.1%) and 65 (56.1 vs. 30.7%), but no interaction between estrous cyclic status and treatments was detected. Crossbred Holstein/Jersey cows had superior fertility than their purebred counterparts during the breeding season. The Presynch and DO protocols resulted in similar fertility with no overall difference between the presynchronization methods however, limiting the length of proestrus to 58 h reduced P/AI in the 5-d timed AI protocol when cows had their estrous cycle presynchronized with Presynch but not with DO.
Publisher: American Dairy Science Association
Date: 04-2013
Abstract: The objectives of this study were to determine the effect of supplemental progesterone on fertility in lactating dairy cows lacking a corpus luteum (CL) at the initiation of the timed artificial insemination (AI) program. Holstein cows were subjected to the 5-d timed AI program (d -8 GnRH, d -3 and -2 PGF2α, d 0 GnRH and AI). Cows had their ovaries scanned by ultrasonography on d -8 and those bearing a CL were considered to be in diestrus (DI n=946). Cows that lacked a CL on d -8 were assigned to remain as untreated control (CON n=234) or receive 2 controlled internal drug release (CIDR) inserts containing progesterone (2CIDR n=218) from d -8 to -3, as a single insert has been proven insufficient to modulate fertility in cows without CL. Blood was analyzed for progesterone and estradiol concentrations. Pregnancy was diagnosed on d 34 and 62 after AI. Progesterone concentrations during the timed AI program were lowest for CON, intermediate for 2CIDR, and highest for DI. Supplementation increased progesterone concentrations between d -7 and -3 compared with CON (2.65 vs. 0.51 ng/mL). Ovulation to the first GnRH was not affected by treatment. However, a greater proportion of CON and 2CIDR cows had a new CL on d -3 compared with DI cows (66.7 vs. 61.9 vs. 52.0%). In cows with a new CL, the diameter of the ovulatory follicle was larger for CON than 2CIDR, and intermediate for DI (18.7 vs. 16.5 vs. 17.7 mm). Concentrations of estradiol on d -3 did not differ among treatments however, DI cows had greater estradiol concentrations at AI compared with CON or 2CIDR cows. Pregnancy per AI was less for CON compared with 2CIDR or DI on d 32 (30.8 vs. 46.8 vs. 49.9%) and 64 (28.6 vs. 43.7 vs. 47.3%), indicating that supplementation with progesterone reestablished fertility in cows lacking a CL on d -8. A greater proportion of nonpregnant CON cows had a short reinsemination interval compared with 2CIDR or DI (11.1 vs. 3.5 vs. 5.7%). Treatment did not affect pregnancy loss between d 34 and 62 of gestation. A single ultrasound exam was effective in identifying a low-fertility cohort of cows based on the absence of CL at the first GnRH injection of the timed AI protocol. Progesterone supplementation with 2 CIDR inserts increased progesterone in plasma to 2.65 ng/mL and restored fertility in lactating dairy cows lacking a CL at the initiation of the timed AI program similar to that of cows in diestrus.
Publisher: American Dairy Science Association
Date: 11-2015
Abstract: The objectives were to evaluate the effects of synchronizing estrus and ovulation to implement a timed artificial insemination (AI) at first insemination on reproductive performance and cost per pregnancy in dairy heifers. Six hundred eleven Holsteins heifers at approximately 400 d of age from 3 farms were enrolled in the study. Six days before moving to the breeding pens, heifers were allocated randomly to AI after detected estrus from study d 0 to 84 (CON, n=306), or to timed AI for first AI followed by detected estrus for the remainder of the 84-d study (TAI, n=305). Heifers receiving TAI were enrolled in the 5-d timed AI protocol on study d -6 (d -6, GnRH and a progesterone insert d -1, PGF2α and insert removal d 0, PGF2α d 2, GnRH + AI), and they were allowed to be bred the day before scheduled timed AI if detected in estrus. Starting on study d 0, estrus was detected daily. Heifers in estrus were inseminated on the same morning as detected estrus. Control heifers not inseminated by study d 7 received PGF2α and this treatment was repeated every 2 wk until AI. The study lasted 84 d to allow a period of breeding equivalent to four 21-d estrous cycles. A herd budget accounting for inputs for both treatments was created to determine the cost per pregnancy. Sensitivity analysis compared economic differences between the 2 treatments under different input scenarios when detection of estrus after the first AI varied from 50 to 80%. Interval to first AI was 8 d shorter for TAI than for CON. Pregnancy at first AI did not differ between treatments (CON=58.3 vs. TAI=62.8%). In contrast, TAI increased pregnancy per AI (P/AI) compared with CON in heifers inseminated with sex-sorted semen (CON=31.6 vs. TAI=54.8%). The 21-d cycle insemination rate was greater for TAI (91.4%) than for CON (82.4%), even when evaluated after the first 21 d in the study (CON=68.2 vs. TAI=77.1%). The increased insemination rate improved the 21-d cycle pregnancy rate from 47.9% in CON to 57.2% in TAI heifers. In fact, the hazard of pregnancy was 60% greater for TAI than CON. The increased pregnancy rate in TAI reduced the median days to pregnancy by 12 d (CON=2.0 vs. TAI=14.0) and increased the proportion of pregnant heifers by 6.3 percentage points by study d 84 (CON=85.2 vs. TAI=91.5%). The cost per pregnancy was $17.00 less for TAI than CON. The sensitivity analysis indicated that TAI was economically more advantageous to produce a pregnancy compared with CON. Only when insemination rate after the first 21 d of breeding was very high and P/AI was relatively low did the cost per pregnancy become similar for the 2 treatments. Collectively, inseminating all heifers within 2 d of breeding with the 5-d timed AI protocol maintains P/AI, improves pregnancy rate, and reduces cost per pregnancy compared with insemination after detected estrus.
Publisher: American Dairy Science Association
Date: 02-2004
Publisher: American Dairy Science Association
Date: 11-2009
Abstract: The objectives were to estimate heritabilities and genetic variances for anovulation at ~50 d in milk and pregnancy loss occurring between first and second pregnancy diagnoses after artificial insemination. Data were originally collected for trials on reproductive management. Anovulation data consisted of 5,818 records from 13 studies in 8 herds with an overall prevalence of 23.3%. A Bayesian approach using Markov Chain Monte Carlo methods was used in mixed threshold models for both traits. The statistical model for anovulation included fixed effects [parity, herd-study-treatment, and body condition score (BCS)], covariates (inbreeding and milk yield), and random effects (sire and residual). A second statistical model included all terms in the first model except BCS. In addition, 2 bivariate, mixed sire models were used to analyze anovulation with BCS and anovulation with milk yield. The posterior mean heritability estimate for anovulation was 0.171 [posterior standard deviation (PSD) = 0.052]. Correlations of anovulation with milk yield were as follows: genetic = 0.168, PSD = 0.187 residual = -0.046, PSD = 0.022 and phenotypic = -0.036. Bivariate analysis of BCS with anovulation showed a genetic correlation (-0.301, PSD = 0.177) and phenotypic correlation (-0.192, PSD = 0.019). Pregnancy-loss data consisted of 3,775 records from 14 studies in 8 herds with an overall prevalence of 14.4%. Analysis of pregnancy loss used a sire-maternal grandsire threshold model with embryo survival as the subject of analysis. Independent variables consisted of fixed effects (parity and herd-study), covariates (embryo and maternal inbreeding), and random effects (sire of embryo, maternal grandsire of embryo, and residual). In addition, separate sire models were analyzed using embryo as the subject and cow as the subject of analysis. The sire-maternal grandsire model yielded a heritability for direct effect of 0.489 (PSD = 0.221) and for maternal effects of 0.166 (PSD = 0.113). In this study, the breeding value variance for embryo effects was 3 times the breeding value variance for maternal effects, indicating that, at the level of breeding values, the embryo's ability to survive has a greater effect on pregnancy loss than does the cow's ability to maintain the pregnancy. These results suggest that genetic improvement of reproductive performance could be enhanced by selection for fundamental measures such as abnormally long periods of postpartum anovulation and pregnancy loss. Larger studies of these traits are needed to obtain parameter estimates with greater precision.
Publisher: American Dairy Science Association
Date: 10-2011
Abstract: Two experiments evaluated the effects of the first GnRH injection of the 5-d timed artificial insemination (AI) program on ovarian responses and pregnancy per AI (P/AI), and the effect of timing of the final GnRH to induce ovulation relative to AI on P/AI. In experiment 1, 605 Holstein heifers were synchronized for their second insemination and assigned randomly to receive GnRH on study d 0 (n = 298) or to remain as untreated controls (n = 307). Ovaries were scanned on study d 0 and 5. All heifers received a controlled internal drug-release (CIDR) insert containing progesterone on d 0, a single injection of PGF(2α) and removal of the CIDR on d 5, and GnRH concurrent with timed AI on d 8. Blood was analyzed for progesterone at AI. Pregnancy was diagnosed on d 32 and 60 after AI. Ovulation on study d 0 was greater for GnRH than control (35.4 vs. 10.6%). Presence of a new corpus luteum (CL) at PGF(2α) injection was greater for GnRH than for control (43.1 vs. 20.8%), although the proportion of heifers with a CL at PGF(2α) did not differ between treatments and averaged 87.1%. Progesterone on the day of AI was greater for GnRH than control (0.50 ± 0.07 vs. 0.28 ± 0.07 ng/mL). The proportion of heifers at AI with progesterone <0.5 ng/mL was less for GnRH than for control (73.8 vs. 88.2%). The proportion of heifers in estrus at AI did not differ between treatments and averaged 66.8%. Pregnancy per AI was not affected by treatment at d 32 or 60 (GnRH = 52.5 and 49.8% vs. control = 54.1 and 50.0%), and pregnancy loss averaged 6.0%. Responses to GnRH were not influenced by ovarian status on study d 0. In experiment 2, 1,295 heifers were synchronized for their first insemination and assigned randomly to receive a CIDR on d 0, PGF(2α) and removal of the CIDR on d 5, and either GnRH 56 h after PGF(2α) and AI 16h later (OVS56, n = 644) or GnRH concurrent with AI 72 h after PGF(2α) (COS72 n = 651). Estrus at AI was greater for COS72 than for OVS56 (61.4 vs. 47.5). Treatment did not affect P/AI on d 32 in heifers displaying signs of estrus at AI, but COS72 improved P/AI compared with OVS56 (55.0 vs. 47.6%) in those not in estrus at AI. Similarly, P/AI on d 60 did not differ between treatments for heifers displaying estrus, but CO S72 improved P/AI compared with OVS56 (53.0 vs. 44.7%) in those not in estrus at AI. Administration of GnRH on the first day of the 5-d timed AI program resulted in low ovulation rate and no improvement in P/AI when heifers received a single PGF(2α) injection 5 d later. Moreover, extending the proestrus by delaying the final GnRH from 56 to 72 h concurrent with AI benefited fertility of dairy heifers that did not display signs of estrus at insemination following the 5-d timed AI protocol.
Publisher: American Dairy Science Association
Date: 03-2016
Abstract: The objective of this series of studies was to investigate the effects of inflammatory diseases occurring before breeding on the developmental biology and reproductive responses in dairy cows. Data from 5 studies were used to investigate different questions associating health status before breeding and reproductive responses. Health information for all studies was composed of the incidence of retained fetal membranes, metritis, mastitis, lameness, and respiratory and digestive problems from parturition until the day of breeding. Retained placenta and metritis were grouped as uterine disease (UTD). Mastitis, lameness, digestive and respiratory problems were grouped as nonuterine diseases (NUTD). Study 1 evaluated the effect of disease before artificial insemination (AI), anovulation before synchronization of the estrous cycle, and low body condition score at AI on pregnancy per AI, as well as their potential interactions or additive effects. Study 2 investigated the effect of site of inflammation (UTD vs. NUTD) and time of occurrence relative to preantral or antral stages of ovulatory follicle development, and the effect of UTD and NUTD on fertility responses of cows bred by AI or by embryo transfer. Study 3 evaluated the effect of disease on fertilization and embryonic development to the morula stage. Study 4 evaluated the effect of disease on preimplantation conceptus development as well as secretion of IFN-τ and transcriptome. Study 5 investigated the effect of diseases before AI on the transcript expression of interferon-stimulated genes in peripheral blood leukocytes during peri-implantation stages of conceptus development after first AI postpartum. Altogether, these studies demonstrated that inflammatory disease before breeding reduced fertilization of oocytes and development to morula, and impaired early conceptus development to elongation stages and secretion of IFN-τ in the uterine lumen. Diseases caused inflammation-like changes in transcriptome of conceptus cells, increased risk of pregnancy loss, and reduced pregnancy or calving per breeding. Moreover, the effects on reproduction were independent of cyclic status before synchronization of the estrous cycle and body condition score at breeding, which all had additive negative effects on fertility of dairy cows. Occurrence of disease at preantral or at antral stages of ovulatory follicle development had similar detrimental effects on pregnancy results. The carryover effects of diseases on developmental biology might last longer than 4 mo. Reduced oocyte competence is a likely reason for carryover effects of diseases on developmental biology, but impaired uterine environment was also shown to be involved.
Publisher: American Dairy Science Association
Date: 2022
Abstract: Objectives were to evaluate the effects of follicular wave and progesterone concentration on growth of the ovulatory follicle, conceptus elongation, uterine IFN-τ concentration, and transcriptome of conceptus and endometrium of pregnant cows on d 17 of gestation. Nonlactating nonpregnant Holstein cows were assigned randomly to one of 3 treatments: ovulation of a first-wave follicle (FW, n = 15) ovulation of a first-wave follicle and progesterone supplementation (FWP4, n = 12) and ovulation of a second-wave follicle (SW, n = 19). Ovulation of a first- or second-wave follicle was achieved by initiating the Ovsynch protocol (d -9 GnRH, d -2 and -1 PGF
Publisher: Bioscientifica
Date: 05-2017
DOI: 10.1530/REP-16-0642
Abstract: The objectives were to determine the effects of supplementing docosahexaenoic acid (DHA)-rich algae on reproduction of dairy cows. Holstein cows were assigned randomly to either a control ( n = 373) or the same diet supplemented daily with 100 g/cow of an algae product containing 10% DHA (algae, n = 366) from 27 to 147 days postpartum. Measurements included yields of milk and milk components, fatty acids (FA) profiles in milk fat and plasma phospholipids, resumption of ovulation by 57 days postpartum, pregnancy per artificial insemination (AI) and expression of interferon-stimulated genes in leukocytes. Feeding algae increased resumption of estrous cyclicity (77.6 vs 65.9%) and pregnancy at first AI (47.6 vs 32.8%) in primiparous cows. Algae increased pregnancy per AI in all AI in both primiparous and multiparous cows (41.6 vs 30.7%), which reduced days to pregnancy by 22 days (102 vs 124 days) compared with control cows. Pregnant cows fed algae had greater expression of RTP4 in blood leukocytes compared with those in pregnant control cows. Feeding algae increased the incorporation of DHA, eicosapentaenoic acid, conjugated linoleic acid isomers cis -9 trans -11, trans -10 cis -12 and total n-3 FA in phospholipids in plasma and milk fat. Yields of milk and true protein increased by 1.1 kg/day and 30 g/day respectively, whereas fat yield decreased 40 g/day in algae compared with that in control. Supplementing DHA-rich algae altered the FA composition of lipid fractions and improved reproduction in dairy cows. The benefits on reproduction might be mediated by enhanced embryo development based on changes in interferon-stimulated gene expression.
Publisher: Elsevier
Date: 2011
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.THERIOGENOLOGY.2008.12.005
Abstract: Lactating Holstein cows (n=135) were randomly assigned to one of the two sources of supplemental selenium (Se), sodium selenite (SS) or Se yeast (SY), fed at 0.3mg/kg diet dry matter from 25 d before calving to 70 d in milk (DIM), in diets not suboptimal in basal Se concentrations. Cows were evaluated for health daily in the first 10 DIM, and uterine cytology of the previously gravid uterine horn was assessed at 30 DIM. The Ovsynch protocol was initiated at 42 DIM ovarian responses to hormonal treatments were evaluated by ultrasonography. The uteri of cows were flushed 6d after timed AI for collection of embryos and oocytes. Plasma concentrations of Se and progesterone were measured throughout the postpartum period and during the reproductive protocol, respectively, and plasma glutathione peroxidase activity was determined 6d after AI. Concentrations of Se in pre- and postpartum diets ranged from 0.43 to 0.56 mg/kg of dry matter. Incidence of retained placenta, fever, ketosis, mastitis, acute puerperal metritis, clinical endometritis, and subclinical endometritis were not significantly different between treatments. There were no differences between groups in concentrations of Se and progesterone or glutathione peroxidase activity in plasma. Treatment did not influence ovarian responses to the synchronization protocol, fertilization rate, number of blastomeres and live blastomeres, or proportions of grades 1 and 2, degenerated, and degenerated-unfertilized embryos/oocytes. Odds of subclinical endometritis on Day 30 postpartum more than doubled in cows with fever of unknown origin or acute puerperal metritis in the first 10 DIM. Fertilization rate tended to be reduced in cows with subclinical endometritis. In summary, replacing SS with an organic source of Se in diets not suboptimal in basal Se concentrations did not improve Se status, uterine health, fertilization, or embryo quality in early lactation dairy cows.
Publisher: American Dairy Science Association
Date: 12-2020
Publisher: Elsevier BV
Date: 09-2005
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.THERIOGENOLOGY.2012.01.011
Abstract: The objectives were to determine the effects of one or three timed artificial insemination (AI) before natural service (NS) in lactating dairy cows not observed for detection of estrus on hazard of pregnancy, days nonpregnant, and 21-days cycle pregnancy rate. A total of 1050 lactating Holstein cows were subjected to a double Ovsynch program for their first postpartum AI. On the day of first AI (78 ± 3 days in milk), cows were blocked by parity and randomly assigned to receive either one timed AI (1TAI, n = 533) or three timed AI (3TAI, n = 517) before being exposed to NS. Cows assigned to 1TAI were exposed to bulls 7 days after the first AI. Nonpregnant cows in 3TAI were resynchronized with the Ovsynch protocol supplemented with progesterone twice, with intervals between AI of 42 days, before being exposed to NS 7 days after the third AI. Cows were evaluated for pregnancy 32 days after each timed AI, or every 28 days after being exposed to NS. Pregnant cows were re-examined for pregnancy 28 days later (i.e., 60-day gestation). Exposure to heat stress was categorized based on the first AI being performed during the hot or cool season, according to the temperature-humidity index. Body condition was scored at first AI. All cows were allowed a period of 231 days of breeding, after which nonpregnant cows were censored. Pregnancy to the first AI did not differ between 1TAI and 3TAI on Day 60 after insemination (30.8 vs. 33.5%). Cows receiving 3TAI had a 15% greater hazard of pregnancy and a 17% greater 21-days cycle pregnancy rate than 1TAI and these benefits originated from the first 84 days of breeding. These changes in rate of pregnancy reduced the median and mean days nonpregnant by 9 and 10 d, respectively. Despite the long inter-AI interval in cows subjected to 3TAI, reproductive performance was improved compared with a single timed AI and subsequent exposure to NS. In dairy herds that use a combination of AI and NS, allowing cows additional opportunities to AI before onset of breeding with bulls is expected to improve reproductive performance.
Publisher: American Dairy Science Association
Date: 2022
Abstract: The onset of lactation results in a sudden irreversible loss of Ca for colostrum and milk synthesis. Some cows are unable to quickly adapt to this demand and succumb to clinical hypocalcemia, whereas a larger proportion of cows develop subclinical hypocalcemia that predisposes them to other peripartum diseases. The objective of this study was to perform a comprehensive genomic analysis of blood total Ca concentration in periparturient Holstein cows. We first performed a genomic scan and a subsequent gene-set analysis to identify candidate genes, biological pathways, and molecular mechanisms affecting postpartum Ca concentration. Then, we assessed the prediction of postpartum Ca concentration using genomic information. Data consisted of 7,691 records of plasma or serum concentrations of Ca measured in the first, second, and third day after parturition of 959 primiparous and 1,615 multiparous cows that calved between December 2015 and June 2020 in 2 dairy herds. All cows were genotyped with 80k SNPs. The statistical model included lactation (1 to 5+), calf category (male, females, twins), and day as fixed effects, and season-treatment-experiment, animal, and permanent environmental as random effects. Model predictive ability was evaluated using 10-fold cross-validation. Heritability and repeatability estimates were 0.083 (standard error = 0.017) and 0.444 (standard error = 0.028). The association mapping identified 2 major regions located on Bos taurus autosome (BTA)6 and BTA16 that explained 1.2% and 0.7% of additive genetic variance of Ca concentration, respectively. Interestingly, the region on BTA6 harbors the GC gene, which encodes the vitamin D binding protein, and the region on BTA16 harbors LRRC38, which is actively involved in K transport. Other sizable peaks were identified on BTA5, BTA2, BTA7, BTA14, and BTA9. These regions harbor genes associated with Ca channels (CACNA1S, CRACR2A), K channels (KCNK9), bone remodeling (LRP6), and milk production (SOCS2). The gene-set analysis revealed terms related to vitamin transport, calcium ion transport, calcium ion binding, and calcium signaling. Genomic predictions of phenotypic and genomic estimated breeding values of Ca concentration yielded predictive correlations up to 0.50 and 0.15, respectively. Overall, the present study contributes to a better understanding of the genetic basis of postpartum blood Ca concentration in Holstein cows. In addition, the findings may contribute to the development of novel selection and management strategies for reducing periparturient hypocalcemia in dairy cattle.
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.DOMANIEND.2011.05.005
Abstract: Lipopolysaccharide (LPS) modulates innate immunity through alteration of cytokine production by immune cells. The objective of this study was to examine the effect of exogenous conjugated linoleic acid (CLA) and PPAR-γ agonist, rosiglitazone, on LPS-induced tumor necrosis factor α (TNF-α) production by cultured whole blood from prepubertal Holstein heifers (mean age, 5.5 mo). Compared with unstimulated cells, addition of LPS (10 μg/mL) to the culture medium increased (P<0.03) peripheral blood mononuclear cell proliferation≤2.5-fold. Coincubation with interferon γ (5 ng/mL) further stimulated (P<0.01) the lymphoproliferative response to LPS. Lipopolysaccharide increased (P<0.01) TNF-α concentration in cultured whole blood in a dose- and time-dependent manner. The greatest TNF-α stimulation occurred after 12 h of exposure to 1 μg/mL LPS. Coincubation with trans-10, cis-12 CLA isomer (100 μM) or rosiglitazone (10 μM), a PPAR-γ agonist, decreased (P<0.01) LPS-induced TNF-α production by 13% and 29%, respectively. Linoleic acid and cis-9, trans-11 CLA isomer had no detectable effects on LPS-induced TNF-α production in cultured bovine blood. The PPAR-γ agonist-induced TNF-α attenuation was reversed when blood was treated with both rosiglitazone and GW9662, a selective PPAR-γ antagonist. Addition of rosiglitazone to the culture medium tended to reduce nuclear factor-κ Bp65 concentration in nuclear and cytosolic extracts isolated from cultured peripheral blood mononuclear cells. Results show that LPS is a potent inducer of TNF-α production in bovine blood cells and that trans-10, cis-12 CLA and PPAR-γ agonists may attenuate the pro-inflammatory response induced by LPS in growing dairy heifers. Additional studies are needed to fully characterize the involvement of nuclear factor-κ B in LPS signaling in bovine blood cells.
Publisher: American Dairy Science Association
Date: 10-2019
Abstract: The main objective of this study was to determine the association of dry matter intake as percentage of body weight (DMI%BW) and energy balance (EB) prepartum (-21 d relative to parturition) and postpartum (28 d) with calving disorders (CDZ dystocia, twins, and stillbirths n = 101) and metritis (n = 114). For this, DMI%BW and EB were the independent variables and CDZ and metritis were the dependent variables. A secondary objective was to evaluate prepartum DMI%BW and EB as predictors of CDZ and metritis. For this, CDZ and metritis were the independent variables and DMI%BW and EB were the dependent variables. Data from 476 cows from 9 experiments were compiled. Cows that developed CDZ had lesser postpartum DMI%BW from d 3 to 12 and lesser energy-corrected milk (ECM) than cows that did not develop CDZ. Dry matter intake as percentage of BW and EB prepartum did not affect the odds of CDZ. Cows with metritis had lesser prepartum DMI%BW and EB. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average EB in the last 3 d prepartum increased the odds of having metritis by 8%. The average DMI%BW and EB during the last 3 d prepartum produced significant cut-offs to predict metritis postpartum, which were ≤1.6%/d and ≤2.5 Mcal/d, respectively. Cows that developed metritis had lesser overall postpartum DMI%BW and ECM and lesser EB from d 2 to 5 and from d 7 to 11 than cows that did not develop metritis. The main limitation in this study is that the time-order of disease relative to DMI%BW and ECM is inconsistent such that postpartum outcomes were measured before and after disease, which was diagnosed at variable intervals after calving. In summary, prepartum DMI%BW and EB were associated with and were predictors of metritis although the effect sizes were small for metritis, and calving disorders and metritis were associated with decreased DMI%BW and ECM postpartum.
Publisher: American Dairy Science Association
Date: 02-2021
Publisher: American Dairy Science Association
Date: 10-2019
Abstract: The main objective of this study was to determine the association of dry matter intake as percentage of body weight (DMI%BW) and energy balance (EB) prepartum (-21 d relative to parturition) and postpartum (28 d) with ketosis (n = 189) and clinical mastitis (n = 79). For this, DMI%BW and EB were the independent variables and ketosis and clinical mastitis were the dependent variables. A secondary objective was to evaluate prepartum DMI%BW and EB as predictors of ketosis and clinical mastitis. For this, ketosis and clinical mastitis were the independent variables and DMI%BW and EB were the dependent variables. Data from 476 cows from 9 experiments were compiled. Clinical mastitis was diagnosed if milk from 1 or more quarters was abnormal in color, viscosity, or consistency, with or without accompanying heat, pain, redness, or swelling of the quarter or generalized illness, during the first 28 d postpartum. Ketosis was defined as the presence of acetoacetate in urine that resulted in any color change [5 mg/dL (trace) or higher] in the urine test strip (Ketostix, Bayer, Leverkusen, Germany). Cows that developed ketosis had lesser DMI%BW and lesser EB on d -5, -3, -2, and -1 than cows without ketosis. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average of EB in the last 3 d prepartum increased the odds of having ketosis by 8 and 5%, respectively. Cut-offs for DMI%BW and EB during the last 3 d prepartum to predict ketosis were established and were ≤1.5%/d and ≤1.1 Mcal/d, respectively. Cows that developed ketosis had lesser postpartum DMI%BW and EB and greater energy-corrected milk (ECM) than cows without ketosis. Cows that developed clinical mastitis had lesser DMI%BW but similar prepartum EB compared with cows without clinical mastitis. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average EB in the last 3 d prepartum increased the odds of having clinical mastitis by 10 and 8%, respectively. The average DMI%BW and EB during the last 3 d prepartum produced significant cut-offs to predict clinical mastitis postpartum, which were ≤1.2%/d and ≤1.0 Mcal/d, respectively. Cows that developed clinical mastitis had lesser postpartum DMI%BW from d 3 to 15 and on d 17 greater EB on d 18, from d 21 to 23, and on d 26 and lesser ECM. The main limitation in this study is that the time-order of disease relative to DMI%BW and ECM is inconsistent such that postpartum outcomes were measured before and after disease, which was diagnosed at variable intervals after calving. In summary, measures of prepartum DMI were associated with and were predictors of ketosis and clinical mastitis postpartum, although the effect sizes were small.
Publisher: Elsevier BV
Date: 07-2012
Publisher: Elsevier BV
Date: 07-2002
DOI: 10.1016/S0739-7240(02)00160-1
Abstract: Pregnancy rate to the Ovsynch protocol can be improved if cows are presynchronized (i.e., two PGF(2alpha) injections given 14 days apart and the second injection of PGF(2alpha) given 12 days prior to the first GnRH of the Ovsynch program) so that a greater proportion of cows during the Ovsynch protocol ovulate to the first GnRH injection and have a CL at PGF(2alpha) injection. Pregnancy rates were normal in anestrous cows (39.6%) if they ovulated to both injections of GnRH. Estradiol cypionate (ECP) can be used to replace GnRH to induce ovulation as a modification of the Presync-Ovsynch program (i.e., Presync-Heatsynch). Pregnancy rates after TI were 37.1+/-5.8% for Presync-Ovsynch compared to 35.1+5.0% for Presync-Heatsynch. Use of ECP to induce ovulation was an alternative to GnRH in which greater uterine tone, ease of insemination and occurrence of estrus, improved acceptance by inseminators. A GnRH agonist (Deslorelin 750 microg) implant inserted at 48 h after injection of PGF(2alpha), as a component of the Ovsynch protocol, induced ovulation, development of a normal CL and delayed follicular growth until 24 d after implant insertion. Utilization of Deslorelin implants (450 microg and 750 microg) to induce ovulation compared to GnRH (100 microg) within the Ovsynch protocol resulted in 27 d pregnancy rates (GnRH 100 microg, 39% Deslorelin implants 450 microg, 40% and 750 microg, 27.5%) with 12.7%, 5.0% and 9.5% embryonic losses by 41 d of pregnancy, respectively. Induction of an accessory CL with injection of hCG on day 5 after insemination improved conception rates by 7.1%. Bovine somatotrophin injected at first insemination following a Presync-Ovsynch program in cycling-lactating dairy cows increased 74 days pregnancy rates (57.1%>42.6%).
Publisher: Springer Science and Business Media LLC
Date: 2004
Publisher: Elsevier BV
Date: 12-2016
Publisher: Elsevier BV
Date: 07-2010
DOI: 10.1016/J.ANIREPROSCI.2010.03.007
Abstract: The objectives of the present study were to evaluate factors associated with estrous synchronization responses and pregnancy per insemination (P/AI) in Bos indicus beef cows submitted to progesterone-based fixed-time artificial insemination (FTAI) protocols. A total of 2388 cows (1869 Nellore and 519 crossbred NellorexAngus) from 10 commercial farms were evaluated to determine the relationships among breed, body condition score (BCS) on the first day of the FTAI protocol, the occurrence of estrus between progesterone device removal and FTAI, and diameter of largest ovarian follicle (LF) at FTAI on estrous synchronization responses and P/AI. Cows (n=412 primiparous 1976 multiparous) received an intravaginal device containing progesterone or an ear implant containing norgestomet (a progestin), and an injection of estradiol at the beginning of the estrous synchronization protocol. Body condition was scored using a 1-5 scale on the first day of the FTAI protocol and at 30-60 days postpartum. Females received 300IU of equine chorionic gonadotropin (eCG) and PGF(2alpha) on the day the progesterone device/implant was removed and were inseminated 48-60h later. At insemination, cows (n=2388) were submitted to an ultrasonographic exam to determine the diameter of the LF. Follicles were classified into four categories based on mean and standard deviation (SD) of the LF (LF1=two SD below the mean LF2=mean minus one SD LF3=mean plus one SD LF4=two SD above the mean). Ovulation rate was determined in a subset of cows (n=813) by three consecutive ultrasonographic exams: (1) at time of progesterone device/implant removal, (2) at time of FTAI and (3) 48h after FTAI. Ovulation was defined as the disappearance of a large follicle (>or=8.0mm) that was previously recorded. Estrus was determined in a subset of the cows (n=445) by the activation of a detection of estrous patch placed on the tail head on the day of progesterone device/implant removal. Pregnancy was diagnosed 30 days after FTAI. Pregnancy was influenced (P=0.001) by follicle diameter [LF1=27.5% (81/295), LF2=46.6% (328/705), LF3=57.9% (647/1118), LF4=63.3% (171/270)] and the occurrence of estrus [estrus=67.7% (174/257) and no estrus=36.2% (68/188)]. Follicle diameter at FTAI influenced ovulation rate [LF1=42.5% (34/80), LF2=73.9% (161/218), LF3=95.8% (407/425), LF4=97.8% (88/90)], the occurrence of estrus [LF1=54.8% (51/93), LF2=33.6% (43/128), LF3=68.9% (126/183), LF4=90.2% (37/41)] and P/AI among cows that had ovulations [LF1=32.4% (11/34), LF2=50.3% (81/161), LF3=60.0% (244/407), LF4=68.2% (60/88)]. Improving estrous responses between progesterone device withdrawal and FTAI and increasing the diameter of the LF at FTAI may be important aspects to achieve improved estrous synchronization responses and P/AI following progesterone rogestin and estradiol based FTAI protocols in suckled Bos indicus cows.
Publisher: American Dairy Science Association
Date: 03-2010
Abstract: The objective was to determine if the 5-d Co-Synch+CIDR (controlled internal drug releasing insert) protocol can be used in dairy heifers for a synchronized timed artificial insemination (TAI) with one injection of PGF(2alpha) for first and second services. In experiment 1, heifers were assigned randomly to receive 1 (n=295) or 2 (n=298) injections of PGF(2alpha) in the 5-d Co-Synch+CIDR protocol. Corpus luteum (CL) regression was measured in one replicate (n=218). No difference in pregnancy per TAI (P/TAI 46.1 and 48.6%) or CL regression (86.9 and 92.8%) was detected for 1 versus 2 injections of PGF(2alpha), respectively. In experiment 2, nonpregnant heifers (n=86) were assigned to a resynchronized 5-d Co-Synch+CIDR with 1 PGF(2alpha)/TAI or insemination at detected estrus. There was no difference in P/TAI (52.2 and 55%) between groups. In experiment 3, nonpregnant heifers (n=110) were assigned randomly to receive a CIDR (n=54) or no CIDR insert (n=56) in the 5-d Co-Synch protocol for resynchronization of TAI. Pregnancy per TAI was lower without the CIDR device (39.3 vs. 51.8%). In a commercial field evaluation, 416 heifers were synchronized for the first and resynchronized TAI with the 5-d Co-Synch+CIDR protocol with 1 injection of PGF(2alpha). Pregnancy per TAI on d 60 was 58.2 and 47.5% for first and second TAI, respectively there was a sire effect to the second TAI. In conclusion, the 5-d Co-Synch+CIDR protocol with 1 injection of PGF(2alpha) is an effective reproductive management program for first and second TAI in dairy heifers.
Publisher: Elsevier
Date: 2020
Publisher: American Dairy Science Association
Date: 09-2023
Publisher: American Dairy Science Association
Date: 09-2008
Abstract: The objectives of this study were to evaluate the effect of reproductive protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcomes of breeding programs. Holstein heifers (n = 534), 13 +/- 1 mo of age, were randomly assigned to 1 of 4 reproductive protocols. On the day of enrollment (d 0), heifers were palpated per rectum and received a score according to the maturity of their reproductive tract (1 = prepubertal 2 = peripubertal and 3 = puber-tal). Estrous detection-control heifers (CON, n = 146) received no treatment and were inseminated on detection of estrus for 28 d. Prostaglandin F(2alpha)-treated heifers (PGED, n = 137) received 1 injection of PGF(2alpha) on d 0 and were inseminated on detection of estrus heifers not in-seminated by d 14 received a second injection of PGF(2alpha) and were observed for estrus and artificial insemination (AI) for an additional 14 d. Heifers enrolled in the estrous detection-timed AI (EDTAI, n = 140) treatment received a controlled internal drug-release (CIDR) insert on d 0, and 7 d later, the CIDR was removed and all heifers received an injection of PGF(2alpha), heifers received AI on detection of estrus, and those not inseminated by 72 h after PGF(2alpha) received an injection of GnRH concurrent with AI. Heifers in the GnRH-timed AI (GTAI, n = 111) treatment received 1 injection of GnRH on d 0, on d 6 heifers received a CIDR insert and injections of GnRH and PGF(2alpha), on d 13 the CIDR was removed and heifers received an injection of PGF(2alpha), and 48 h later all heifers received an injection of GnRH and AI. Pregnancy was diagnosed at 32 +/- 3 and 62 +/- 3 d after AI. Cost of reproductive protocols and their economic outcomes were calculated for a 28 d period beginning at enrollment. Heifers in the PGED treatment were inseminated at a faster rate than CON heifers. A smaller proportion of prepubertal and peripubertal heifers were inseminated within 14 d of enrollment compared with pubertal heifers. Pregnancy per AI of CON and PGED heifers was greater compared with EDTAI and GTAI heifers. Proportion of GTAI heifers pregnant at the end of the 28-d breeding program was or tended to be smaller compared with PGED and CON heifers, respectively. Heifers in the CON and PGED treatments had the smallest cost per pregnancy followed by heifers in the EDTAI and GTAI treatments, respectively. When different scenarios were evaluated, however, the mean cost per pregnancy was smallest for PGED heifers. Cost per pregnancy generated was greatest for prepubertal heifers, whereas pubertal heifers had the smallest cost per pregnancy generated. Treatment of dairy heifers with PGF(2alpha) every 14 d until insemination and pregnancy results in the best economic outcomes, and screening heifers according to RTS may prove beneficial to identify heifers that may not be pubertal and would have compromised reproductive and economic performance in a breeding program.
Publisher: American Dairy Science Association
Date: 04-2017
Abstract: Objectives were to evaluate associations among gestation length (GL) and performance in Holstein cows and their offspring. A total of 8,095 Holstein cows and 3,635 female offspring born alive on 2 farms using only artificial insemination (AI) were evaluated. Gestation length averaged 276 ± 6 d in the 8,095 dams, and it was categorized as short (SGL at least 1 SD below the population mean mean = 266 d, range 256 to 269 d), average (AGL population mean ± 1 SD mean = 276 d, range 270 to 282 d), or long (LGL at least 1 SD above the population mean mean = 285 d, range 283 to 296 d). Responses evaluated in dams included incidence of diseases within 90 d in milk (DIM), pregnancy at first AI and by 300 DIM, and time to pregnancy. Milk yield and removal from the herd by culling or death were recorded for the first 300 DIM. Responses evaluated in female offspring born alive included removal from the herd and reproductive performance. Within primiparous cows, those with SGL had greater incidence of stillbirth, retained placenta, and metritis than primiparous with AGL or LGL however, within multiparous cows, those with SGL or LGL had greater incidence of dystocia, stillbirth, retained placenta, and metritis than cows with AGL. Morbidity and rate of morbidity were greater for SGL and LGL than AGL. Rate of removal of dams from the herd was 38% faster for SGL than AGL. Milk production was greatest in AGL cows, but responses depended on parity. For primiparous cows, milk production was less in SGL and LGL than in AGL (AGL = 35.4, SGL = 34.6, LGL = 33.0 ± 0.4 kg/d), whereas for multiparous cows, production was less in SGL but greater in LGL than in AGL (AGL = 41.6, SGL = 38.6, LGL = 42.4 ± 0.3 kg/d). A smaller proportion of cows with SGL received at least one AI, but pregnancy at first AI did not differ among groups. Rate of pregnancy was 11% slower for LGL multiparous than for AGL multiparous. By 300 DIM, pregnancy was greater in AGL than SGL. Pregnancy by 300 DIM in multiparous cows was also greater for AGL than LGL. Heifers from dams with GL that deviated from AGL had greater mortality postweaning (AGL = 3.2 vs. SGL = 6.5 vs. LGL = 5.4%). The rate of removal from the herd was greater for SGL (adjusted hazard ratio = 1.78 95% CI: 1.26 to 2.52) and LGL (adjusted hazard ratio = 2.00 95% CI: 1.45 to 2.76) than for AGL heifers. Pregnancy at first AI was lowest for LGL and by 500 d of age a larger proportion of AGL heifers were pregnant than LGL (AGL = 82.3 vs. SGL = 79.2 vs. LGL = 74.0%). Cows with GL within 1 SD of the population mean (270 to 282 d) had improved health, production, and reproduction. Heifers from cows with GL within 1 SD of the population mean had improved health and reproduction. Gestation length affects performance of both dams and their offspring.
Publisher: American Dairy Science Association
Date: 06-2022
Abstract: The objectives were to evaluate the associations between hepatic triacylglycerol content and production, blood metabolites, incidence of diseases, reproduction, and survival in Holstein cows. Data were collected from 4 experiments including 329 cows in which hepatic tissue was s led with a mean (± standard deviation) of 8.3 ± 1.5 d postpartum (6 to 11 d) and analyzed for triacylglycerol concentration. The mean (± standard deviation) concentration was 4.4 ± 2.8% on a wet basis and ranged from 0.4 to 16.1%. Intakes of dry matter (DM), energy balance, body weight (BW), body condition (BCS), productive performance, and incidence of diseases were evaluated for the first 105 d postpartum, whereas blood metabolites were assayed in the first 21 d postpartum. Reproductive performance and survival were monitored in the first 300 d postpartum. Mixed models were fitted to the data to investigate the linear and quadratic associations of hepatic triacylglycerol concentration with responses of interest. Increased concentration of hepatic triacylglycerol was associated with a quadratic increase in yields of milk, energy-corrected milk (ECM), and milk components. A change in hepatic triacylglycerol from 2.5 to 7.5% of the wet tissue was associated with an increase in yield of ECM of 1.8 kg/d, and with 0.2 kg more ECM per kg of DM intake. However, the increased efficiency was accompanied by decreases in DM intake, BCS, more exacerbated losses of BW, and a more negative body energy change. Increased concentration of hepatic triacylglycerol was associated with a quadratic increase in blood fatty acids and a linear increase in blood β-hydroxybutyrate concentrations, concurrent with linear decreases in concentrations of glucose and total Ca in blood. Moreover, a change in hepatic triacylglycerol from 2.5 to 7.5% was associated with linear increases in the relative risk of hyperketonemia by 2.5 times (15.2 vs. 37.5%), hypocalcemia by 1.7 times (30.3 vs. 52.4%), metritis by 2.1 times (12.5 vs. 25.7%), and diagnosis of multiple diseases postpartum by 2.4 times (8.7 vs. 21.1%). Survival in the herd by 300 d postpartum tended to decrease from 91.1 to 86.3% with an increase in hepatic triacylglycerol from 2.5 to 7.5% of the wet tissue, but no association was observed between hepatic triacylglycerol and measures of reproduction in the first 300 d postpartum. Concentrations of hepatic triacylglycerol in early lactation varied substantially, and increments resulted in quadratic association with productive performance, but at the expense of tissue reserves as those cows had increased tissue catabolism and risk of diseases that reduced survival.
Publisher: Oxford University Press (OUP)
Date: 06-04-2018
DOI: 10.1093/JAS/SKY123
Publisher: Oxford University Press (OUP)
Date: 04-08-2023
Abstract: Endometrial inflammation is associated with reduced pregnancy per artificial insemination (AI) and increased pregnancy loss in cows. It was hypothesized that induced endometritis alters histotroph composition and induces inflammatory signatures on conceptus that compromise development. In Experiment 1, lactating cows were assigned to control (CON n = 23) or to an intrauterine infusion of Escherichia coli and Trueperella pyogenes (ENDO n = 34) to induce endometritis. Cows received AI 26 days after treatment, and the uterine fluid and conceptuses were collected on day 16 after AI. In Experiment 2, Holstein heifers were assigned to CON (n = 14) or ENDO (n = 14). An embryo was transferred on day 7 of the estrous cycle, and uterine fluid and conceptuses were recovered on day 16. Composition of histotroph and trophoblast and embryonic disc gene expression were assessed. Bacterial-induced endometritis in lactating cows altered histotroph composition and pathways linked to phospholipid synthesis, cellular energy production, and the Warburg effect. Also, ENDO reduced conceptus length in cows and altered expression of genes involved in pathogen recognition, nutrient uptake, cell growth, choline metabolism, and conceptus signaling needed for maternal recognition of pregnancy. The impact of ENDO was lesser on conceptuses from heifers receiving embryo transfer however, the affected genes and associated pathways involved restricted growth and increased immune response similar to the observed responses to ENDO in conceptuses from lactating cows. Bacterial-induced endometrial inflammation altered histotroph composition, reduced conceptus growth, and caused embryonic cells to activate survival rather than anabolic pathways that could compromise development.
Publisher: American Dairy Science Association
Date: 2015
Abstract: The objective of this study was to evaluate factors associated with resumption of ovarian cyclicity within 21 days in milk (DIM) in dairy cows. Cows (n=768) from 2 herds in north Florida had their ovaries scanned at 17±3, 21±3, and 24±3 DIM. Cows that had a corpus luteum ≥20mm at 17±3 or at 21±3 DIM or that had a corpus luteum 28 kg of BW within 14 DIM. In model 3, variables associated with greater cyclicity by 21±3 DIM were absence of metabolic problems and dry period ≤76 d. In summary, cyclicity by 21±3 DIM was negatively associated with calving in winter or spring, primiparity, metritis, metabolic or digestive problems, loss of >28 kg of body weight, and a dry period >76d. Strategies preventing extended dry period length and loss of BW, together with reductions in the incidence of metritis as well as metabolic and digestive problems should improve early cyclicity postpartum.
Publisher: American Dairy Science Association
Date: 09-1997
Publisher: American Dairy Science Association
Date: 03-2020
Abstract: It is often suggested that the benefits of supplemental rumen-protected choline (RPC) might be greater in cows predisposed to fatty liver, such as those that are overconditioned however, limited data support this suggestion. Therefore, the hypothesis of this study was that responses to supplementing RPC to transition dairy cows is not dependent on the degree of fatness prepartum. Objectives were to evaluate the effects of supplementing RPC to transition dairy cows according to body condition score (BCS) prepartum on production and metabolic responses. Data from 2 randomized block experiments that evaluated the effects of RPC supplementation during the transition period were combined. Within each experiment, cows were assigned randomly to receive 0 (CTRL) or 12.9 g/d choline ion in an RPC form (CHOL) daily top-dressed onto the diet from 21 d prepartum to 21 d postpartum. Body condition was evaluated twice prepartum before enrollment and the mean value was used as an explanatory variable for statistical analyses. Data were collected for the last 21 d of gestation and the first 105 d postpartum. The BCS (mean ± standard deviation) prepartum were 3.51 ± 0.29 and 3.51 ± 0.32 for CTRL and CHOL, respectively, and ranged from 2.69 to 4.25. A total of 215 cows were enrolled in the respective experiments and contributed data for the incidence of diseases, whereas 192 cows contributed data for analyses of production responses, plasma metabolites, and liver composition. Irrespective of BCS, supplementing transition diets with CHOL increased yields of milk by 1.8 kg/d, fat by 0.08 kg/d, lactose by 0.08 kg/d, true protein by 0.04 kg/d, energy-corrected milk (ECM) by 1.9 kg/d, and fat-corrected milk by 2.1 kg/d. The improvements in productive performance were not followed by increased dry matter intake or measures of lipomobilization. Therefore, CHOL cows were more efficient in converting dry matter intake into ECM. Feeding CHOL increased concentration of hepatic triacylglycerol (CTRL = 3.23 vs. CHOL = 3.87% wet basis) in the first 21 d postpartum. Overconditioned cows were more prone to having exacerbated lipomobilization and increased prevalence and incidence of fatty liver, but no interactions between treatment and BCS were observed for body weight, BCS, or concentrations of metabolites in plasma or hepatic triacylglycerol. Treatment did not affect incidence of clinical diseases. Opposite to common suggestions, cows with increased hepatic triacylglycerol content also had increased yields of milk and ECM in the first 105 d postpartum. Collectively, these findings indicate that the effects of RPC supplementation during the transition period are independent of the degree of fatness of dairy cows prepartum. The findings also suggest that the effects on productive performance are not necessarily mediated by improvements in markers of metabolic health or reductions in hepatic triacylglycerol.
Publisher: American Dairy Science Association
Date: 2020
Abstract: The objectives were to evaluate the effects of feeding different amounts of supplemental live yeast (LY) on performance and digestion of cows under heat stress. Sixty Holstein cows, 27 multiparous and 33 primiparous, were blocked by parity and milk yield in the first 20 d in milk (DIM) and randomly assigned to receive 0, 0.5, or 1.0 g/d of LY, resulting in daily intakes of 0, 14.2, and 37.6 billion cells, respectively, of Saccharomyces cerevisiae strain CNCM I-1077 from 30 to 107 DIM. Cows were milked twice daily, dry matter intake (DMI) and milk yield were measured daily, and milk components, body weight, and body condition were measured weekly. Blood was s led weekly and plasma analyzed for concentrations of glucose, fatty acids, urea N, haptoglobin, serum amyloid A, and acid-soluble protein. Digestibility of nutrients was measured in the last 2 wk of the experiment. Ruminal fluid was collected on 2 consecutive days 6 h after the morning feeding for measurements of pH, concentrations of short chain fatty acids, and NH
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Dairy Science Association
Date: 09-2014
Abstract: The objective was to evaluate the in idual and combined effect of anovulation and cytological endometritis (CTE) on the reproductive performance of dairy cows. A total of 1,569 cows from 3 data sets were used. In data set 1, 403 Holstein cows from 5 dairies in New York were used. In data set 2, 750 Holstein cows from 2 dairies, one in Florida and one in California were used. In data set 3, 416 dairy cows, 165 Holsteins, 36 Jerseys, and 215 Holstein-Jersey crossbreeds from a grazing dairy in Florida were used. Cyclicity and CTE was determined at 35±3 (data set 2) or 49±3 d in milk (data sets 1 and 3). A variable (VarCycCTE) containing all 4 possible permutations between cyclicity (cyclic = Cyc anovular = Anov) and CTE (present = CTE absent = Healthy) was created. In the combined data set (sets 1, 2, and 3), pregnancy per artificial insemination (P/AI) diagnosed at 30 to 38 d after first AI was affected by VarCycCTE, with AnovCTE cows having decreased P/AI compared with CycHealthy cows (21.3 vs. 46.7%), whereas AnovHealthy (37.9%) and CycCTE cows (36.0%) had intermediate P/AI. Pregnancy per artificial insemination for the in idual data sets and for pregnancy diagnosed at 63 to 74 d after artificial insemination followed a similar pattern. Pregnancy loss was not affected by VarCycCTE. Hazard of pregnancy up to 300 d in milk was affected by VarCycCTE in the combined data sets 1 and 2, with AnovCTE [hazard ratio (HR)=0.55], AnovHealthy cows (HR=0.71), and CycCTE (HR=0.8) having decreased hazard of pregnancy compared with CycHealthy cows. Median days open were 200, 159, 145, and 121 for AnovCTE, AnovHealthy, CycCTE, and CycHealthy, respectively. Hazard of pregnancy for the in idual data sets followed a similar pattern. In summary, both anovulation and CTE were negatively associated with reproductive performance and, when combined, they had an additive negative effect.
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.THERIOGENOLOGY.2011.07.023
Abstract: The objective was to compare the observed and expected combined effects of clinical mastitis before timed artificial insemination (TAI) and low body condition at 70 d postpartum (dpp) on pregnancy loss in dairy cows. Cows were examined for pregnancy by ultrasonographic examination 28-32 d after TAI the presence of an embryo with a heartbeat was the criterion used to determine pregnancy. Cows diagnosed pregnant were re-examined by transrectal palpation of the uterus and its contents 28 d later to confirm pregnancy status and to identify pregnancy loss. Eighty-eight (17%) of 512 cows were diagnosed with pregnancy loss. Cows affected with clinical mastitis before insemination and a body condition score (BCS)≤2.75 at 70 dpp were 2.03 times more likely to experience pregnancy loss, compared to cows without clinical mastitis and with a BCS>2.75 (RR=2.03 95% CI=1.15, 3.60 P=0.01). This observed combined effect for pregnancy loss (RR=2.03) was higher than the expected combined effect based on adding (RR=1.39) or multiplying (RR=1.42) absolute independent excesses due to clinical mastitis or low body condition.
Publisher: Colegio Brasileiro de Reproducao Animal - CBRA
Date: 2016
Publisher: American Dairy Science Association
Date: 2018
Abstract: The objectives of this experiment were to evaluate the effect of feeding a culture of Saccharomyces cerevisiae on rumen metabolism and digestibility when cows are fed diets varying in starch content. Four lactating Holstein cows were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Treatments were low starch (LS 23% of diet DM) and no yeast culture (YC LS-control), LS and 15 g of YC/d (LS-YC), high starch (HS 29% of diet DM) and no YC (HS-control), and HS and 15 g of YC/d (HS-YC). Periods lasted 28 d, with the last 9 d for data collection. Days 20 to 24 were used to determine production, nutrient flow, and digestibility. On d 25, 3 kg of corn grain DM was placed in the rumen 1 h before the morning feeding, and yields of milk and milk components were measured after the challenge. Blood was s led -1, 3, 7, and 11 h relative to the morning feeding on d 24 and 25. Rumen pH was measured continuously on d 24 and 25. Rumen papillae were collected on d 24 and 28 to quantify mRNA expression of select genes. Supplementing YC increased yields of milk (26.3 vs. 29.6 kg/d), energy-corrected milk (ECM 26.5 vs. 30.3 kg/d), fat (0.94 vs. 1.08 kg/d), true protein (0.84 vs. 0.96 kg/d), and ECM/dry matter intake (1.15 vs. 1.30) compared with the control but did not affect dry matter intake (22.6 vs. 22.9 kg/d). Cows fed HS had increased milk true protein percentage (3.18 vs. 3.31%) and yield (0.87 vs. 0.94 kg/d) compared with cows fed LS. Feeding HS-YC increased the proportion of dietary N incorporated into milk true protein from 24.9% in the other 3 treatments to 29.6%. Feeding HS increased the concentration of propionate (21.7 vs. 32.3 mM) and reduced that of NH
Publisher: American Dairy Science Association
Date: 2018
Abstract: The objectives were to evaluate the effects of a culture of Saccharomyces cerevisiae (YC) on lactation performance of cows fed diets differing in starch content. Fifty-six Holstein cows at 42 d postpartum were blocked by parity and milk production and randomly assigned to 1 of 4 treatments, low starch (23% diet DM) and no YC (LS-control), low starch and 15 g/d of YC (LS-YC), high starch (29% diet DM) and no YC (HS-control), and high starch and 15 g/d of YC (HS-YC). The experiment lasted 14 wk. Blood was s led twice weekly during the first 5 wk in the experiment. Feeding behavior was evaluated in 2 consecutive days when cows were 33 d in the experiment. On d 92 in the experiment, cows were challenged with 3 kg of corn grain DM immediately before the morning feeding. Blood was s led in the first 12 h after the challenge. Rumen fluid was collected 5 h after the challenge, and pH, ammonia N, short-chain fatty acids, and lactate concentrations were quantified. Lactation performance was measured daily before and after the challenge. Supplementation with YC increased yields of 3.5% fat-corrected milk and energy-corrected milk by 2.2 and 2.0 kg/d, and the increments were observed in both low- and high-starch diets. Feeding HS tended to decrease milk fat content (LS = 3.88 vs. HS = 3.73%), but increased concentration (LS = 2.87 vs. HS = 3.00%) and yield (LS = 1.11 vs. HS = 1.20 kg/d) of milk true protein. Feeding YC increased yields of fat and true protein in milk by 100 and 60 g/d. Energy balance, body weight, and feed efficiency did not differ with treatments. Feeding HS reduced eating time (LS = 177 vs. HS = 159 min/12 h) and intermeal interval (LS = 103 vs. HS = 82 min), but tended to increase eating rate (LS = 139 vs. HS = 150 g/min). Interactions were detected between level of starch and YC for ruminating time, meal duration, and meal size because within LS, feeding YC increased ruminating time 23 min/12 h, but reduced meal duration 6 min/meal and meal size 0.7 kg/meal. Concentrations of glucose in plasma increased (LS = 62.1 vs. HS = 63.8 mg/dL), whereas those of urea N decreased (LS = 10.1 vs. HS = 9.4 mg/dL) with feeding HS compared with LS in the first 5 wk in the experiment, and the same responses were observed after the challenge with corn grain. After the challenge, rumen pH was less and short-chain fatty acid concentrations were greater in cows fed HS compared with those fed LS however, supplementing YC to high-starch diets increased rumen pH (HS-control = 5.72 vs. HS-YC = 6.12) and reduced concentrations of lactate in rumen fluid (HS-control = 7.72 vs. HS-YC = 1.33 mM) and haptoglobin in plasma 28%. Feeding YC improved lactation performance irrespective of the level of dietary starch and reduced the risk of subacute rumen acidosis induced by a grain challenge when cows were fed a high-starch ration.
Publisher: Oxford University Press (OUP)
Date: 06-08-2020
Publisher: American Dairy Science Association
Date: 12-2010
Abstract: Objectives were to investigate 2 intervals from induction of ovulation to artificial insemination (AI) and the effect of supplemental progesterone for resynchronization on fertility of lactating dairy cows subjected to a 5-d timed AI program. In experiment 1, 1,227 Holstein cows had their estrous cycles presynchronized with 2 injections of PGF(2α) at 46 and 60 d in milk (DIM). The timed AI protocols were initiated with GnRH at 72 DIM, followed by 2 injections of PGF(2α) at 77 and 78 DIM and a second injection of GnRH at either 56 (OVS56) or 72h (COS72) after the first PGF(2α) of the timed AI protocols. All cows were time-inseminated at 72h after the first PGF(2α) injection. Pregnancy was diagnosed on d 32 and 60 after AI. In experiment 2, 675 nonpregnant Holstein cows had their estrous cycles resynchronized starting at 34 d after the first AI. Cows received the OVS56 with (RCIDR) or without (RCON) supplemental progesterone, as an intravaginal insert, from the first GnRH to the first PGF(2α). Pregnancy diagnoses were performed on d 32 and 60 after AI. During experiment 2, subsets of cows had their ovaries scanned by ultrasonography at the first GnRH, the first PGF(2α), and second GnRH injections of the protocol. Blood was s led on the day of AI and 7 d later, and concentrations of progesterone were determined in plasma. Cows were considered to have a synchronized ovulation if they had progesterone 2.26 ng/mL on the day of AI and 7 d later, respectively, and if no ovulation was detected between the first PGF(2α) and second GnRH injections during resynchronization. In experiment 1, the proportion of cows detected in estrus at AI was greater for COS72 than OVS56 (40.6 vs. 32.4%). Pregnancy per AI (P/AI) did not differ between OVS56 (46.4%) and COS72 (45.5%). In experiment 2, cows supplemented with progesterone had greater P/AI compared with unsupplemented cows (51.3 vs. 43.1%). Premature ovulation tended to be greater for RCON than RCIDR cows (7.5 vs. 3.6%), although synchronization of the estrous cycle after timed AI was similar between treatments. Timing of induction of ovulation with GnRH relative to insemination did not affect P/AI of dairy cows enrolled in a 5-d timed AI program. Furthermore, during resynchronization starting on d 34 after the first AI, supplementation with progesterone improved P/AI in cows subjected to the 5-d timed AI protocol.
Publisher: American Dairy Science Association
Date: 10-2005
Publisher: American Dairy Science Association
Date: 10-2012
Publisher: American Dairy Science Association
Date: 08-2023
Publisher: American Dairy Science Association
Date: 06-2016
Abstract: The objectives were to compare development and transcriptome of preimplantation conceptuses 15 d after synchronized ovulation and artificial insemination (AI) according to the genetic background of the cow and estrous cyclicity at the initiation of the synchronization program. On d 39±3 postpartum, Holstein cows that were anovular (HA n=10), Holstein cows that were estrous cyclic (HC n=25), and Jersey/Holstein crossbred cows that were estrous cyclic (CC n=25) were randomly selected in a grazing herd and subjected to the Ovsynch protocol. All cows were inseminated on d 49±3 postpartum, which was considered study d 0. Blood was s led and analyzed for concentrations of progesterone, estradiol, insulin, and insulin-like growth factor 1 (IGF-1) on study d -10, -3, -1, 7, and 15 relative to AI. On study d 15, uteri were flushed and recovered fluid had IFN-τ concentrations measured and subjected to metabolomic analysis. Morphology of the recovered conceptuses was evaluated, and mRNA was extracted and subjected to transcriptome microarray analysis. Compared with HC, CC presented greater concentrations of progesterone and estradiol in plasma, with corpora lutea and preovulatory follicles of similar size. Conceptuses from CC were larger, tended to secrete greater amounts of IFN-τ, and had greater transcript expression of peroxisome proliferator-activated receptor gamma (PPARγ), an important transcription factor that coordinates lipid metabolism and elongation at preimplantation development. In addition, pregnant CC had greater concentrations of anandamide in the uterine flush, which might be important for elongation of the conceptus and early implantation. Conceptuses from HA were also longer and secreted greater amounts of IFN-τ than conceptuses from HC, likely because of the distinct progesterone profiles before and after AI. Nonetheless, anovular cows had reduced concentrations of IGF-1 in plasma, and their conceptuses presented remarkable transcriptomic differences. Some of the altered transcripts suggest that conceptus cells from anovular cows might be under greater cellular stress and presented markers suggesting increased apoptosis and autophagy, which could lead to increased mortality after d 15 of development. Estrous cyclicity had more impact on transcriptome of bovine conceptus than genetic background, and the developmental changes observed during the preimplantation period might be linked to differences in fertility among groups.
Publisher: Wiley
Date: 18-05-2010
DOI: 10.1111/J.1439-0531.2008.01220.X
Abstract: Objectives were to evaluate risk factors affecting ovulatory responses and conception rate to the Ovsynch protocol. Holstein cows, 466, were submitted to the Ovsynch protocol [day 0, GnRH-1 day 7, prostaglandin (PG) F(2alpha) day 9, GnRH-2] and 103 cows were inseminated 12 h after GnRH-2. Information on parity, days in milk at GnRH-1, body condition, milk yield, exposure to heat stress, pre-synchronization with PGF(2alpha) and the use of progesterone insert from GnRH-1 to PGF(2alpha) was collected. Ovaries were scanned to determine responses to treatments. Overall, 54.7%, 10.6%, 2.2%, 81.1%, 9.0%, 91.5% and 36.9% of the cows ovulated to GnRH-1, multiple ovulated to GnRH-1, ovulated before GnRH-2, ovulated to GnRH-2, multiple ovulated to GnRH-2, experienced corpus luteum (CL) regression and conceived, respectively. Ovulation to GnRH-1 was greater in cows without a CL at GnRH-1, cows with follicles >19 mm and cows not pre-synchronized with PGF(2alpha) 14 days before GnRH-1. Multiple ovulations to GnRH-1 increased in cows without CL at GnRH-1 and cows with follicles 2.75 and cows that ovulated to GnRH-2. Strategies that optimize ovulation to GnRH-2, such as increased ovulation to GnRH-1, should improve response to the Ovsynch protocol.
Publisher: Oxford University Press (OUP)
Date: 2001
Abstract: The objectives were to evaluate effects of human chorionic gonadotropin (hCG) (3,300 IU i.m.) administered on d 5 after AI on CL number, plasma progesterone concentration, conception rate, and pregnancy loss in high-producing dairy cows. Following the synchronization of estrus and AI, 406 cows were injected with either hCG or saline on d 5 after AI in a randomized complete block design. Blood s ling and ovarian ultrasonography were conducted once between d 11 and 16 after AI. Pregnancy diagnoses were performed on d 28 by ultrasonography and on d 45 and 90 after AI by rectal palpation. Treatment with hCG on d 5 resulted in 86.2% of the cows with more than one CL compared with 23.2% in controls. Plasma progesterone concentrations were increased by 5.0 ng/mL in hCG-treated cows. The presence of more than one CL increased progesterone concentration in hCG-treated cows but not in controls. Conception rates were higher for hCG-treated cows on d 28 (45.8 > 38.7%), 45 (40.4 > 36.3%), and 90 (38.4 > 31.9%) after AI. Treatment with hCG improved conception rate in cows losing body condition between AI and d 28 after Al. Pregnancy losses were similar between treatment groups. Treatment with hCG on d 5 after AI induces accessory CL, enhances plasma progesterone concentration, and improves conception rate of high-producing dairy cows.
Publisher: American Dairy Science Association
Date: 10-2010
Abstract: Objectives were to evaluate the effects of inseminating cows observed in estrus following a PGF(2α)-based presynchronization protocol on reproductive and lactation performance. Weekly, Holstein cows (260 primiparous and 379 multiparous) were balanced by parity, body condition score at 3 d in milk (DIM), and previous lactation milk yield (multiparous cows) and assigned randomly to either of 2 reproductive programs. All cows received 2 injections of PGF(2α) at 35 and 49 DIM and a controlled internal drug release insert containing progesterone from 42 to 49 DIM. Cows assigned to the short voluntary waiting period (SVWP) treatment were inseminated if observed in estrus after the second injection of PGF(2α) of the presynchronization protocol, and those not inseminated were submitted to a timed artificial insemination (TAI) protocol (GnRH 62 DIM, PGF(2α) 69 DIM, GnRH 71 DIM, and TAI 72 DIM), whereas cows assigned to the long voluntary waiting period (LVWP) were all submitted to the TAI protocol and were TAI at 72 DIM. Plasma progesterone was determined at 35, 49, and 62 DIM for evaluation of interval from parturition to resumption of cyclicity. Pregnancy was diagnosed weekly at 32 and 60 d after first AI and at 42 d after subsequent inseminations. Percentage of SVWP cows inseminated in estrus was 58.9% and the interval from parturition to first AI was shorter for SVWP cows (64.7±0.4 vs. 74.2±0.5 DIM). Cows cyclic by 49 and 62 DIM were more likely to be inseminated in estrus than those anovular by 62 DIM (67.9, 61.0, and 32.8%, respectively) and cyclic cows by 49 and 62 DIM had shorter interval from parturition to first AI than anovular cows (62.6±0.7, 63.1±1.2, and 70.1±1.1 DIM). Treatment did not affect pregnancy per AI after first postpartum AI or the rate at which cows became pregnant. Cows that resumed cyclicity by 49 DIM had greater pregnancy per AI than cows still anovular by 62 DIM and became pregnant at a faster rate than cows that resumed cyclicity by 62 DIM and those still anovular by 62 DIM. Inseminating cows that displayed estrus after the presynchronization protocol did not affect reproductive performance compared with submission of 100% of cows to a TAI protocol.
Publisher: Elsevier BV
Date: 03-2004
Publisher: American Dairy Science Association
Date: 10-2023
Publisher: American Dairy Science Association
Date: 04-2008
Abstract: Objectives were to determine effects of feeding a culture of Saccharomyces cerevisiae on performance, health, and immunocompetence of calves in the first 70 d of age. Holstein calves (n = 512) at 2 +/- 1 d of age were randomly assigned to yeast culture (YC, 218 females and 37 males) or control (223 females and 34 males). Yeast culture was fed at 2% of the grain dry matter. All calves received colostrum during the first 24 h, pasteurized milk thereafter until 60 d of age, and grain was fed ad libitum for the first 70 d of age. Calves were housed in in idual hutches, and grain intake was measured 5 d/wk. Body weight was measured at 5, 30, and 68 d of age, and attitude and fecal consistency were scored daily. Incidence and duration of health disorders and treatments were recorded. Neutrophil phagocytic and killing activities and antibody response to immunization with ovalbumin were measured. Concentrations of glucose and 3-hydroxybutyrate were measured in plasma. Grain intake did not differ between treatments and averaged 908 g/d throughout the study. Body weight change, concentrations of glucose, and 3-hydroxybutyrate did not differ between YC and control. Minor effects on neutrophil function were observed, and YC tended to increase the number of phagocytized bacteria and killing of phagocytized bacteria but did not influence humoral immune response. Attitude scores were similar between treatments throughout the study. Almost all calves experienced mild diarrhea during the study, but feeding YC improved fecal scores, reduced days with watery feces, incidence of fever and diarrhea, and risk of health disorders. Because of the high incidence of diarrhea, mortality preweaning was also high, but YC improved survival of calves by decreasing mortality rate past 13 d of age. Income at the end of the study was improved by $48/calf with YC. Feeding yeast culture in grain improved health, minimized frequency of health treatments, and reduced risk of morbidity and mortality in dairy calves.
Publisher: American Dairy Science Association
Date: 11-1999
Publisher: American Dairy Science Association
Date: 05-2021
Publisher: American Dairy Science Association
Date: 08-2023
Publisher: American Dairy Science Association
Date: 08-2023
Publisher: American Dairy Science Association
Date: 11-2009
Abstract: The objectives were to evaluate the effect of supplemental progesterone during a timed artificial insemination (TAI) protocol on pregnancy per insemination and pregnancy loss. Lactating dairy cows from 2 dairy herds were presynchronized with 2 injections of PGF(2alpha) 14 d apart, and cows observed in estrus following the second PGF(2alpha) injection were inseminated (n = 1,301). Cows not inseminated by 11 d after the end of the presynchronization were submitted to the TAI protocol (d 0 GnRH, d 7 PGF(2alpha), d 8 estradiol cypionate, and d 10 TAI). On the day of the GnRH of the TAI protocol (study d 0), cows were assigned randomly to receive no exogenous progesterone (control = 432), one controlled internal drug-release (CIDR) insert (CIDR1 = 440), or 2 CIDR inserts (CIDR2 = 440) containing 1.38 g of progesterone each from study d 0 to 7. Blood was s led on study d 0 before insertion of CIDR for determination of progesterone concentration in plasma, and cows with concentration or =1.0 ng/mL were classified as high progesterone (HP). From a subgroup of 240 cows, blood was s led on study d 3, 7, 17 and 24 and ovaries were examined by ultrasonography on study d 0 and 7. Pregnancy was diagnosed at 38 +/- 3 and 66 +/- 3 d after AI. Data were analyzed including only cows randomly assigned to treatments and excluding cows that were inseminated after the second PGF(2alpha) injection. The proportion of cows classified as HP at the beginning of the TAI protocol was similar among treatments, but differed between herds. Concentrations of progesterone in plasma during the TAI protocol increased linearly with number of CIDR used, and the increment was 0.9 ng/mL per CIDR. The proportion of cows with plasma progesterone > or =1.0 ng/mL on study d 17 was not affected by treatment, but a greater proportion of control than CIDR-treated cows had asynchronous estrous cycles following the TAI protocol. Treatment with CIDR inserts, however, did not affect pregnancy at 38 +/- 3 and 66 +/- 3 d after AI or pregnancy loss.
Publisher: American Dairy Science Association
Date: 11-2008
Abstract: Our objectives were to compare reproductive responses of dairy cows receiving timed artificial insemination (AI) either at 48 or 72 h after induction of luteolysis and supplemented or not with estradiol cypionate (ECP). Holstein cows (971) had their estrous cycles presynchronized with injections of PGF(2alpha) at 37 and 51 d in milk (DIM) and then received an injection of GnRH at 64 DIM and an injection of PGF(2alpha) at 71 DIM. Cows were then assigned to a 2 x 2 factorial randomized block experiment cows in the CoSynch 48 h (CoS48) received a final injection of GnRH concurrent with timed AI 48 h after PGF(2alpha), whereas cows in the CoSynch 72 h (CoS72) received GnRH and timed AI 72 h after PGF(2alpha). Half of the cows in each CoSynch protocol received an injection of 1 mg of ECP 24 h after PGF(2alpha). Therefore, the 4 treatments were as follows: CoS48-NECP (n = 240), CoS72-NECP (n = 246), CoS48-ECP (n = 245), and CoS72-ECP (n = 240). Blood was s led at 7 d before and at the first GnRH of the CoSynch from all cows for analysis of progesterone concentration in plasma. Cows were classified as anovular when progesterone was less than 1.0 ng/mL in both s les. Blood was also s led during proestrus from a subset of 123 cows to measure concentrations of estradiol and at 7 d after timed AI to measure concentrations of progesterone. Ovaries from the same subset of 123 cows were examined by ultrasonography to determine ovulatory follicle diameter and incidence of ovulation. Pregnancy was diagnosed at 40 and 68 d after AI. Prevalence of cyclic cows was 72.4% and was similar among treatments. Concentrations of estradiol increased after ECP treatment and at 72 h of proestrus with CoS72. Pregnancy at 40 and 68 d after AI and pregnancy loss were not affected by timing of AI or supplemental ECP. Delaying timed AI to 72 h and supplementation with ECP increased the proportion of cows displaying estrus at AI, and cows detected in estrus had increased pregnancy per AI associated with improved ovulation and increased postovulatory progesterone concentration. These results indicate that extending the proestrus by delaying timed AI from 48 to 72 h plus supplemental ECP, despite increased expression of estrus at timed AI, did not improve reproductive performance of lactating dairy cows at first AI.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.TVJL.2011.09.019
Abstract: The objectives of this study were to determine the effects of feeding rumen-protected choline (RPC) to dairy cows on the incidence of disease in early lactation, and on their fertility as measured by return to ovarian cyclicity and pregnancies per insemination (P/AI). In the first experiment, 369 cows were fed 15 g/day of RPC between 25 days pre-calving and 80 days post calving. In the second experiment, 578 primigravid cows were fed 15 g/day of RPC for the last 21 days of gestation only. In both experiments, P/AI were evaluated for the first and second inseminations, and health disorders were monitored daily until 90 days after calving. Return to cyclicity was evaluated in experiment 1 only, on days 51 and 61 post calving. In the first experiment, feeding RPC reduced the incidence of clinical ketosis, mastitis, and morbidity, and the number of cases of mastitis per cow. Feeding RPC did not influence cyclicity and P/AI. In the second experiment, cows fed RPC tended to have greater morbidity than controls because of an increased incidence of metritis and fever, although the incidence of retained fetal membranes was lower. The P/AI for first and second inseminations were similar between treatments. Supplementing the diets of dairy cattle with RPC from before until after calving improved the health of early lactation cows. However, in primigravid cows feeding RPC before calving only had mixed effects on health. Feeding RPC had no beneficial effects on reproduction in either experiment.
Publisher: American Dairy Science Association
Date: 10-2013
Abstract: The objectives of the current study were to investigate the efficacy of PGF₂α as a therapy to reduce the prevalence of subclinical endometritis and improve pregnancy per artificial insemination (P/AI) in cows subjected to a timed artificial insemination (AI) program. A total of 1,342 lactating Holstein dairy cows were allocated randomly at 25 ± 3 d in milk (DIM) to remain as untreated controls (control, n=454) or to receive a single PGF₂α treatment at 39 ± 3 DIM (1PGF, n=474) or 2 treatments with PGF(α at 25 ± 3 and 39 ± 3 DIM (2PGF, n=414). All cows were enrolled in the double Ovsynch program at 48 ± 3 DIM and were inseminated at 75 ± 3 DIM. A subset of 357 cows had uterine s les collected for cytological examination at 25 ± 3, 32 ± 3, and 46 ± 3 DIM to determine the percentage of polymorphonuclear leukocytes (PMNL). Subclinical endometritis was defined by the presence of ≥ 5% PMNL. Vaginal discharge score was evaluated at 25 ± 3 DIM and used to define the prevalence of purulent vaginal discharge. Body condition score was assessed at 25 ± 3 DIM. Pregnancy was diagnosed 32 d after AI and reconfirmed 28 d later. At 32 ± 3 DIM, the prevalence of subclinical endometritis was reduced by treatment with PGF₂α at 25 ± 3 DIM in 2PGF (control=23.5% vs. 1PGF=28.3% vs. 2PGF=16.7%) however, this benefit disappeared at 46 ± 3 DIM, and 14% of the cows remained with subclinical endometritis. One or 2 treatments with PGF₂α did not influence P/AI on d 32 or 60 after timed AI, which averaged 39.9 and 35.2%. Similarly, treatment with PGF₂α had no effect on pregnancy loss between 32 and 60 d of gestation (11.9%). Cows diagnosed with both purulent vaginal discharge and subclinical endometritis had the lowest P/AI and the highest pregnancy loss compared with those diagnosed with only 1 of the 2 diseases or compared with cows having no diagnosis of uterine diseases. Interestingly, subclinical endometritis depressed P/AI and increased pregnancy loss only when it persisted until 46 DIM. On d 32 after AI, cows not diagnosed with subclinical endometritis and those that resolved subclinical endometritis by 46 DIM had greater P/AI than those that remained with subclinical endometritis at 46 DIM (45.4 and 40.0 vs. 25.0%, respectively). Similar to P/AI, cows not diagnosed with subclinical endometritis and those that resolved subclinical endometritis by 46 DIM had less pregnancy loss than those with subclinical endometritis at 46 DIM (9.6 and 13.5 vs. 43.9%, respectively). One or 2 treatments with PGF₂α before initiation of the timed AI program were unable to improve uterine health, P/AI, and maintenance of pregnancy in lactating dairy cows. Cows diagnosed with both purulent vaginal discharge and subclinical endometritis had the greatest depressions in measures of fertility at first AI, particularly when subclinical endometritis persisted in the early postpartum period.
Publisher: American Dairy Science Association
Date: 09-2018
Abstract: The objectives were to evaluate the effects of feeding diets with 2 levels of negative dietary cation-anion differences (DCAD) during the last 42 or 21 d of gestation on performance and metabolism in dairy cows. The hypothesis was that extending feeding from 21 to 42 d and reducing the DCAD from -70 to -180 mEq/kg of dry matter (DM) would not be detrimental to performance. Holstein cows at 230 d of gestation were blocked by parity prepartum (48 entering their second lactation and 66 entering their third or greater lactation) and 305-d milk yield, and randomly assigned to 1 of 4 treatments arranged as a 2 × 2 factorial. The 2 levels of DCAD, -70 or -180 mEq/kg of DM, and 2 feeding durations, the last 21 d (short) or the last 42 d (long) prepartum resulted in 4 treatments, short -70 (n = 29), short -180 (n = 29), long -70 (n = 28) and long -180 (n = 28). Cows in the short treatments were fed a diet with DCAD of +110 mEq/kg of DM from -42 to -22 d relative to calving. After calving, cows were fed the same diet and production and disease incidence were evaluated for 42 d in milk, whereas reproduction and survival was evaluated for 305 d in milk. Blood was s led pre- and postpartum for quantification of metabolites and minerals. Reducing the DCAD linearly decreased prepartum DM intake between -42 and -22 d relative to calving (+110 mEq/kg of DM = 11.5 vs. -70 mEq/kg of DM = 10.7 vs. -180 mEq/kg of DM = 10.2 ± 0.4), and a more acidogenic diet in the last 21 d of the dry period reduced intake by 1.1 kg/d (-70 mEq/kg of DM = 10.8 vs. -180 mEq/kg of DM = 9.7 ± 0.5 kg/d). Cows fed the -180 mEq/kg of DM diet had increased concentrations of ionized Ca in blood on the day of calving (-70 mEq/kg of DM = 1.063 vs. -180 mEq/kg of DM = 1.128 ± 0.020 mM). Extending the duration of feeding the diets with negative DCAD from 21 to 42 d reduced gestation length by 2 d (short = 277.2 vs. long = 275.3 d), milk yield by 2.5 kg/d (short = 40.4 vs. long = 37.9 ± 1.0 kg/d) and tended to increase days open because of reduced pregnancy per artificial insemination (short = 35.0 vs. long = 22.6%). Results suggest that increasing the duration of feeding diets with negative DCAD from 21 to 42 d prepartum might influence milk yield and reproduction of cows in the subsequent lactation, although yields of 3.5% fat- and energy-corrected milk did not differ with treatments. Reducing the DCAD from -70 to -180 mEq/kg of DM induced a more severe metabolic acidosis, increased ionized Ca concentrations prepartum and on the day of calving, and decreased colostrum yield in the first milking, but had no effects on performance in the subsequent lactation. Collectively, these data suggest that extending the feeding of an acidogenic diet beyond 21 d is unnecessary and might be detrimental to dairy cows, and a reduction in the DCAD from -70 to -180 mEq/kg of DM is not needed.
Publisher: American Dairy Science Association
Date: 08-2021
Abstract: The objectives were to determine the effects of dietary cation-anion difference (DCAD) fed to pregnant cows during the last 22 d of gestation on offspring acid-base balance, metabolism, growth, and health preweaning. A total of 132 nulliparous Holstein cows were enrolled at 250 (248 to 253) d of gestation in a randomized block design. Cows were blocked by genomic merit of energy-corrected milk yield and assigned randomly to diets varying in DCAD: +200 (P200, n = 43), -50 (N50, n = 45), or -150 (N150, n = 44) mEq/kg of dry matter (DM). Newborn calves (15 males and 28 females in P200, 22 males and 23 females in N50, and 18 males and 26 females in N150) were followed for the first 7 or 56 d of age if males or females, respectively. Measures of acid-base balance and concentrations of minerals in blood were measured in all calves on d 0 before colostrum feeding, and on d 1, 3, and 7. Each calf was fed 3.78 L of colostrum from the respective treatment, and apparent efficiency of IgG absorption was determined. All calves were weighed at birth, and females were weighed again at 21, 42, and 56 d of age. Concentrations in serum of total calcium (tCa), total magnesium (tMg), and total phosphorus (tP) were measured up to 56 d of age intakes of milk and starter grain DM were measured daily from 21 to 56 d of age and incidence of disease was recorded for the first 56 d of age in females. Treatment did not affect acid-base balance measured in all calves. Calves were born with metabolic and respiratory acidosis, which reversed by 1 d of age. In the first 24 h after birth, blood pH increased from 7.215 to 7.421 and bicarbonate from 26.2 to 31.7 mM, whereas partial pressure of CO
Publisher: American Dairy Science Association
Date: 08-2004
Publisher: Elsevier BV
Date: 2008
Publisher: American Dairy Science Association
Date: 2020
Publisher: American Dairy Science Association
Date: 12-2021
Abstract: Objectives were to determine the effects of 3 different levels of dietary cation-anion difference (DCAD) fed during the last 22 d of gestation to pregnant nulliparous cows on pre- and postpartum acid-base balance, mineral metabolism, and health responses. In all, 132 pregnant nulliparous Holstein cows were enrolled at 250 (248-253) d of gestation, blocked by genomic merit of energy-corrected milk yield, and assigned randomly to diets varying in DCAD: +200 (P200, n = 43), -50 (N50, n = 45), or -150 (N150, n = 44) mEq/kg of dry matter. Dietary treatments were fed until calving, after which cows received the same lactation diet for the first 100 d postpartum. Urine and blood were s led throughout the prepartum period and in the first weeks postpartum, and urine was assessed for pH, whereas blood was analyzed for gases, measures of acid-base balance, minerals, and metabolites. Calcium (Ca) and magnesium (Mg) retention and phosphorus (P) digestibility were evaluated in the last week of gestation and first week of lactation. Incidence of diseases was evaluated for the first 100 d postpartum. Data are presented in sequence as P200, N50, N150 (LSM ± SEM). Reducing the DCAD reduced urine (8.17 vs. 6.50 vs. 5.51 ± 0.11) and blood pH (7.442 vs. 7.431 vs. 7.410 ± 0.004) and induced a state of compensated metabolic acidosis with a reduction in blood HCO
Publisher: American Dairy Science Association
Date: 11-2021
Abstract: Objectives were to determine the effects of 3 levels of dietary cation-anion difference (DCAD) fed prepartum to nulliparous cows on productive and reproductive performance. We enrolled 132 pregnant nulliparous Holstein cows at 250 (248-253) d of gestation in a randomized block design. Cows were blocked by genomic merit of energy-corrected milk yield and assigned randomly to diets varying in DCAD, +200 (P200 n = 43), -50 (N50 n = 45), or -150 (N150 n = 44) mEq/kg of dry matter (DM). Dietary treatments were fed during the last 22 d of gestation and, after calving, postpartum cows received the same lactation diet. Productive performance was evaluated for the first 14 wk of lactation, and reproduction was assessed until 305 d postpartum. Intake of DM prepartum decreased linearly (results presented in sequence as least squares means ± standard error of the mean, P200 vs. N50 vs. N150) with a reduction in DCAD (9.0 vs. 8.9 vs. 8.4 ± 0.1 kg/d), which resulted in linear decreases in net energy balance (0.34 vs. 0.20 vs. -0.36 ± 0.20 Mcal/d), body weight change (1.1 vs. 0.8 vs. 0.3 ± 0.1 kg/d), and mean body weight (652 vs. 649 vs. 643 ± 2 kg) prepartum. Treatment did not affect yield of colostrum (6.3 vs. 5.8 vs. 5.1 ± 0.6 kg) or the contents or yields of fat, protein, lactose, IgG, Ca, or Mg in colostrum. Intake of DM (19.4 vs. 19.2 vs. 19.0 ± 0.2 kg/d), yields of milk (36.6 vs. 36.7 vs. 35.8 ± 0.6 kg/d) or energy-corrected milk (36.7 vs. 36.3 vs. 35.9 ± 0.5 kg/d), feed efficiency (1.93 vs. 1.92 vs. 1.93 ± 0.03 kg of energy-corrected milk per kilogram of DM intake), and content and yield of milk components did not differ among treatments during the first 14 wk of lactation. Prepartum DCAD did not affect the cumulative milk yield by 305 d of lactation (9,653 vs. 10,005 vs. 9,918 ± 196 kg). Of the 132 cows, 40 P200, 45 N50, and 43 N150 received at least 1 artificial insemination (AI), and treatment did not affect pregnancy per AI at first (32.5 vs. 35.6 vs. 37.2%) or all AI (30.6 vs. 33.9 vs. 40.2%), although reducing the DCAD increased the proportion of cows pregnant by 305 d postpartum (76.7 vs. 88.9 vs. 93.2%) without altering the rate of pregnancy. Collectively, manipulating the DCAD of prepartum diets, from +200 to -150 mEq/kg of DM, fed to late gestation nulliparous cows did not affect subsequent lactation productive performance, but may have provided some benefit to reproduction, which warrants further confirmation.
Publisher: Elsevier BV
Date: 03-2013
DOI: 10.1016/J.THERIOGENOLOGY.2012.11.029
Abstract: Two studies were conducted to determine if clinical metritis could be prevented or decreased in at-risk lactating dairy cows by a single treatment with Excede Sterile Suspension (ceftiofur crystalline free acid sterile suspension [CCFA-SS]) administered within 24 hours after an abnormal calving. Study 1 was a preliminary study and study 2 was a clinical trial (designed to confirm the results of study 1). In both studies, abnormal calving was defined as cows that had dystocia (required assistance), twins, abortion, retained fetal membranes for 12 hours or more, or any combination thereof. A randomized block design with cows blocked on order-of-entry within dairy without regard to parity was used in both studies. In study 1, cows that had abnormal calving from six commercial dairies were randomly assigned to either untreated control (N = 122) or 6.6 mg ceftiofur equivalents/kg of body weight sc in the base of the ear (CCFA-SS, N = 121), within 24 hours after calving. Cows with normal calving during the enrollment period received no treatment and were included for observational purposes (N = 122). Health observations and rectal temperatures were recorded daily, and physical examinations were conducted on Days 1 ± 1, 7 ± 2, 14 ± 2, and 21 ± 2, and uterine swabs (for bacterial culture) were collected from a subs le of cows on Days 3 or 4, 7 ± 2, 14 ± 2, and 21 ± 2. These observations were made by treatment-blinded personnel. In study 2, cows with abnormal calving from 12 commercial dairies were assigned to receive either saline (control, N = 247) or CCFA-SS (N = 247) within 24 hours after calving. Health observations and rectal temperatures were recorded daily, and physical examinations were conducted on Days 0 to 2, 7 ± 1, and 14. In study 1, the incidence of metritis on Day 14 ± 2 was 20.2% versus 36.8% for CCFA-SS and control, respectively, with an odds ratio of 2.30 (P < 0.05). In study 2, incidences of metritis on Day 14 were 28.7% versus 43.5% for CCFA-SS and saline, respectively, with an odds ratio of 1.92 (P < 0.05). Rectal temperatures on Days 1 and 2 and the average for the first 6 days were lower (P < 0.05) for CCFA-SS compared with control cows for both studies. Treatment of cows with a single dose of CCFA-SS within 24 hours after abnormal calving reduced the incidence of subsequent metritis in lactating dairy cows.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.JSBMB.2017.02.006
Abstract: Bacterial infection of the mammary gland activates an intracrine vitamin D pathway in macrophages of dairy cows. The active hormone of the vitamin D pathway, 1,25-dihydroxyvitamin D
Publisher: American Dairy Science Association
Date: 11-2022
Publisher: Oxford University Press (OUP)
Date: 05-2015
Abstract: Uterine contamination with bacteria is ubiquitous in the postpartum dairy cow. Nearly one-half of all postpartum dairy cows develop clinical disease resulting in metritis and endometritis, which cause depressed milk production and infertility. The causative links between uterine infection and infertility include a hostile uterine environment, disrupted endocrine signaling, and perturbations in ovarian function and oocyte development. In this review we consider the various mechanisms linking uterine infection with infertility in the dairy cow, specifically 1) innate immune signaling in the endometrium, 2) alteration in endocrine signaling in response to infectious agents, and 3) impacts of infection on ovarian function, oocyte development, and follicular development. Normal ovarian follicular and oocyte development requires a series of temporally and spatially orchestrated events however, several of the cellular pathways required for ovarian function are also used during the innate immune response to bacterial pathogens. We propose that activation of cellular pathways during this immune response has a negative impact on ovarian physiology, which is manifest as infertility detected after the clearance of the bacteria. This review highlights how new insights into infection and immunity in cattle are linked to infertility.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.THERIOGENOLOGY.2012.01.012
Abstract: The objectives were to evaluate pregnancy per AI (P/AI) of dairy cows subjected to the 5-day timed AI protocol under various synchronization and luteolytic treatments. Cows were either presynchronized or received supplemental progesterone during the synchronization protocol, and received a double luteolytic dose of PGF2α, either as one or two injections. In Experiment 1, dairy cows (n=737 Holstein=250, Jersey=80, and crossbred=407) in two seasonal grazing dairy farms were randomly assigned to one of four treatments in a 2×2 factorial arrangement. The day of AI was considered study Day 0. Half of the cows were presynchronized (G6G: PGF2α on Day -16 and GnRH on Day -14) and received the 5-day timed AI protocol using 1 mg of cloprostenol, either as a single injection (G6G-S: GnRH on Day -8, PGF2α on Day -3, and GnRH+AI on Day 0) or ided into two injections of 0.5 mg each (G6G-T: GnRH on Day -8, PGF2α on Day -3 and -2, and GnRH+AI on Day 0). The remaining cows were not presynchronized and received a controlled internal drug-release (CIDR) insert containing progesterone from GnRH to the first PGF2α injection of the 5-day timed AI protocol, and 1 mg of cloprostenol either as a single injection on Day -3 (CIDR-S) or ided into two injections of 0.5 mg each on Days -3 and -2 (CIDR-T). Ovaries were examined by ultrasonography on Days -8 and -3 and plasma progesterone concentrations were determined on Days -3 and 0. In Experiment 2, 655 high-producing Holstein cows had their estrous cycle presynchronized with PGF2α at 46±3 and 60±3 days postpartum and were randomly assigned to receive 50 mg of dinoprost during the 5-day timed AI protocol, either as a single injection or ided into two injections of 25 mg each. Pregnancies per AI were determined on Days 35 and 64 after AI in both experiments. In Experiment 1, presynchronization with G6G increased the proportion of cows with a CL on Day -8 (80.6 vs. 58.8%), ovulation to the first GnRH of the protocol (64.2 vs. 50.2%), and the presence (95.6 vs. 88.4%) and number (1.79 vs. 1.30) of CL at PGF(2α) compared with CIDR cows. Luteolysis was greater for two injections compared to a single PGF2α injection (two PGF2α=95.9 vs. single PGF2α=72.2%), especially in presynchronized cows (G6G-T=96.2 vs. G6G-S=61.7%). For cows not presynchronized, two PGF2α injections had no effect on P/AI (CIDR-S=30.2 vs. CIDR-T=34.3%), whereas for presynchronized cows, it improved P/AI (G6G-S=28.7 vs. G6G-T=45.4%). In Experiment 2, the two-PGF2α injection increased P/AI on Days 35 (two PGF2α=44.5 vs. single PGF2α=36.4%) and 64 (two PGF2α=40.3% vs. single PGF2α=32.6%) after AI. Presynchronization and iding the dose of PGF2α (either cloprostenol or dinoprost) into two injections increased P/AI in lactating dairy cows subjected to the 5-day timed AI protocol.
Publisher: Public Library of Science (PLoS)
Date: 11-2016
Publisher: American Dairy Science Association
Date: 07-2011
Abstract: Objectives were to evaluate the effects of differing progesterone concentrations during follicle development on follicular dynamics, fertilization, and embryo quality. Lactating Holstein cows (n=154) were assigned randomly to 1 of 2 treatments. Cows underwent a presynchronization of the estrous cycle composed of an injection of GnRH concurrently with the placement of a progesterone insert, an injection of PGF(2α) and insert removal 7 d later, and a second injection of GnRH 48 h later (study d -16). All cows were then submitted to a hormonal protocol identical to the presynchronization program starting on d 7 of the estrous cycle (study d -9). Cows enrolled in the high progesterone (HP) treatment received no further treatment. Cows in the low progesterone (LP) treatment received additional PGF(2α) injections on study d -14, -13.5, and -13 and again on study d -9, -7, -6.5, and -6. Ovaries were evaluated by ultrasonography, and blood was s led for concentrations of progesterone and estradiol throughout the study. Uteri were flushed 6 d after artificial insemination (AI) and recovered oocytes-embryos were evaluated. Concentrations of progesterone were less for LP cows from study d -7 to -2 concentrations of estradiol at PGF(2α) and at the last GnRH of synchronization were greater for LP than HP. The proportion of cows in estrus at AI was greater for LP than for HP (38.0 vs. 5.3%). Ovulatory follicles of LP cows had larger diameters at the injections of PGF(2α) (17.2 vs. 14.6mm) and final GnRH (19.4 vs. 16.9%) of the synchronization, which resulted in a larger diameter of the corpus luteum 6 d after AI (24.3 vs. 22.6mm). Double ovulation after the last GnRH of the synchronization was increased in LP (18.6%) compared with HP (4.5%). Fertilization rate was similar and averaged 82.7%. The proportion of embryos and oocytes-embryos classified as grades 1 and 2, proportion of degenerated embryos, and unfertilized-degenerated oocytes-embryos were not different between LP and HP. Number of blastomeres did not differ between LP and HP, but the proportion of live blastomeres tended to be less for LP than HP (94.2 vs. 98.7%). Reducing progesterone concentrations during the synchronization program altered concentrations of estradiol and follicular dynamics, but resulted in similar fertilization and only minor changes in embryo quality.
Publisher: American Dairy Science Association
Date: 07-2011
Abstract: Two experiments evaluated the influence of altering the concentrations of progesterone during the development of the ovulatory follicle on the composition of the follicular fluid, circulating LH and PGF(2α) metabolite (PGFM), and expression of endometrial progesterone receptor and estrogen receptor-α. In both experiments, the estrous cycles were presynchronized (GnRH and progesterone insert followed by insert removal and PGF(2α) 7 d later, and GnRH after 48 h) and cows were then enrolled in 1 of 2 treatments 7 d later (study d -16): high progesterone (HP) or low progesterone (LP). In experiment 1 (n=19), cows had their estrous cycle synchronized starting on study d -9 (GnRH and progesterone insert on d -9, and insert removal and PGF(2α) on d -2). In experiment 2 (n=25), cows were submitted to the same synchronization protocol as in experiment 1, but had ovulation induced with GnRH on study d 0. In experiment 1, plasma was s led on d -4 and analyzed for concentrations of LH the dominant follicle was aspirated on d 0 and the fluid analyzed for concentrations of progesterone, estradiol, and free and total IGF-1. In experiment 2, follicular development and concentrations of progesterone and estradiol in plasma were evaluated until study d 16. Uterine biopsies were collected on d 12 and 16 for progesterone receptor and estrogen receptor-α protein abundance. An estradiol/oxytocin challenge for PGFM measurements in plasma was performed on d 16. In experiments 1 and 2, LP cows had lower plasma concentrations of progesterone and greater concentrations of estradiol, and had larger ovulatory follicle diameter (20.4 vs. 17.2mm) at the end of the synchronization protocol than HP cows. Concentration of LH tended to be greater for LP than HP cows (0.98 vs. 0.84 ng/mL). The dominant follicle of LP cows had greater concentration of estradiol (387.5 vs. 330.9 ng/mL) and a lower concentration of total IGF-1 (40.9 vs. 51.7 ng/mL) than that of HP cows. In experiment 2, estradiol and progesterone concentrations did not differ between treatments from d 0 to 16 however, the proportion of cows with a short luteal phase tended to increase in LP than HP (25 vs. 0%). Concentrations of PGFM were greater for LP than HP. Uterine biopsies had a greater abundance of progesterone receptor, and tended to have less estrogen receptor-α abundance on d 12 compared with d 16. An interaction between treatment and day of collection was detected for estrogen receptor-α because of an earlier increase in protein abundance on d 12. Reduced concentrations of progesterone during the development of the ovulatory follicle altered follicular dynamics and follicular fluid composition, increased basal LH concentrations, and prematurely increased estrogen receptor-α abundance and exacerbated PGF(2α) release in the subsequent estrous cycle.
Publisher: American Dairy Science Association
Date: 08-2023
Publisher: American Dairy Science Association
Date: 04-2015
Abstract: The objectives were to evaluate the effects of injectable vitamin E during the last 3 wk prepartum on the incidence of retained fetal membranes (RFM) and reproductive performance. Dairy cows (n=890), 390 Holsteins (132 nulliparous and 258 parous) and 500 crossbred Holstein × Gyr (199 nulliparous and 301 parous), from 3 dairy farms in Brazil were assigned to the study. In all 3 farms, from October to March, prepartum cows grazed tropical grasses and received 2 kg/d of a mixture of finely ground corn, soybean meal, and minerals and vitamins. From April to September prepartum cows received a total mixed ration composed of corn silage, finely ground corn, soybean meal, and minerals and vitamins. During the prepartum period, cows were fed 280 (farm 1), 390 (farm 2), and 480 IU (farm 3) of supplemental vitamin E per day, and throughout postpartum, cows were fed 370 (farm 1), 500 (farm 2), and 600 (farm 3) IU of supplemental vitamin E. Within each farm, cows were randomly assigned to remain as untreated controls or to receive 3 i.m. injections of 1,000 IU each of dl-α-tocopherol administered at 19.2 ± 4.3, 12.9 ± 3.3, and 6.2 ± 2.9 d before calving (VitE). Blood was s led from 141 cows immediately before enrollment to determine the α-tocopherol and cholesterol statuses. Blood was also s led and analyzed for concentrations of cortisol and nonesterified fatty acids in the last 3 wk of gestation. The serum concentration of α-tocopherol or α-tocopherol:cholesterol ratio did not differ between treatments and averaged 2.97 ± 0.10 μg/mL and 4.46 ± 0.16 × 10(-3), respectively. In total, 53.2% of the cows had an inadequate concentration of serum α-tocopherol based on the 3.0 μg/mL cut-off for adequacy. The risk of RFM decreased as serum α-tocopherol increased. Milk production did not differ between controls and VitE cows. Treatment with injectable α-tocopherol decreased RFM from 20.1 to 13.5%, decreased incidence of stillbirth from 14.9 to 6.8%, and tended to decrease death by 200 d postpartum. VitE cows tended to have improved pregnancy per insemination at first AI (36.7 vs. 30.1%) because of decreased pregnancy loss from 31 to 62 d of gestation (12.5 vs. 20.5%). Despite a similar insemination rate, VitE cows had 22% greater pregnancy rate than control cows. Cows receiving vitamin E had decreased circulating cortisol and nonesterified fatty acids around calving. In summary, when cows were fed limited amounts of supplemental vitamin E, 28 to 48% of the recommendations, prepartum supplementation with injectable α-tocopherol decreased incidence of RFM and improved reproduction.
Publisher: Elsevier
Date: 2002
Publisher: Elsevier BV
Date: 02-2021
Publisher: Oxford University Press (OUP)
Date: 2014
DOI: 10.1095/BIOLREPROD.113.114694
Abstract: Objectives were to evaluate the effects of administering either one or two low doses of slow-release recombinant bovine somatotropin (bST) on hormone concentrations, conceptus development, and fertility in dairy cows. Cows from two farms were detected in estrus on or after 50 days postpartum (n = 1483), inseminated, and enrolled in the study (Day 0). Within farm, cows were blocked by parity and assigned randomly to receive a single placebo injection at insemination (control), a single injection with 325 mg of bST at insemination (S-bST), or two injections with 325 mg of bST administered on Days 0 and 14 (T-bST). From a subset of cows, blood was collected twice weekly from Day 0 to 42 for determination of hormone concentrations and on Day 19 for isolation of leucocytes and analysis of transcript abundance of selected interferon-stimulated genes. Pregnancy was diagnosed on Days 31 and 66, and ultrasonographic morphometry of the conceptus was performed on Days 34 and 48 in a subset of cows. Cows that received T-bST had increased plasma concentrations of GH and IGF1 for 4 wk, increased mRNA expression of ISG15 and RTP4 in leukocytes, earlier rise in the pregnancy-specific protein B in plasma of pregnant cows, increased conceptus size, and enhanced fertility. Cows that received S-bST had increased concentrations of GH and IGF1 for only 2 wk and it was insufficient to alter conceptus development and fertility. In conclusion, supplementation with low doses of bST during the pre- and peri-implantation periods enhanced conceptus development, reduced embryonic losses, and improved fertility in dairy cows.
Publisher: American Dairy Science Association
Date: 04-2015
Abstract: The objectives were to determine the effect of progesterone supplementation on fertility responses in lactating dairy cows without corpora lutea (CL) at initiation of the timed artificial insemination (AI) program. Holstein cows from 5 commercial dairy farms were subjected to the Ovsynch-56 protocol (d -10 GnRH, d -3 PGF2α, d -0.7 GnRH, d 0 AI). Ovaries were scanned by ultrasonography on d -10. Within farm, cows without CL were blocked by pen and assigned randomly to remain as nonsupplemented controls (CON n = 652) or to receive 2 controlled internal drug-release (CIDR) inserts containing 1.38 g of progesterone each from d -10 to -3 (2CIDR n = 642). Cows with CL were randomly selected within pen and used as positive controls as cows in diestrus at the initiation of the Ovsynch protocol (DIEST n = 640). Signs of estrus were detected beginning on d -9 based on removal of tail chalk, and cows in estrus received AI on the same day. Blood s les from subsets of cows on d -10, -9, -7, -5, -3, and 0 (n = 109) and on d 6, 13, and 19 (n = 156) were analyzed for progesterone concentrations. Pregnancy was diagnosed on d 32 and 60 after AI. The average progesterone concentration during the timed AI program was lowest for CON, intermediate for 2CIDR, and highest for DIEST (0.92, 2.77, and 4.93 ng/mL, respectively). The proportions of cows that ovulated in response to the first GnRH (63.6, 61.1, and 47.2%, respectively) and that had a new CL on d -3 at PGF2α injection (72.4, 67.9, and 47.4%, respectively) were greater for CON and 2CIDR compared with DIEST, respectively. The diameter of the ovulatory follicle and the proportion of cows that ovulated in response to the second GnRH did not differ among treatments. A greater proportion of CON and 2CIDR cows were detected in estrus at AI compared with DIEST cows (35.8, 39.6, and 30.6%, respectively). Pregnancy per AI was less for CON compared with 2CIDR and DIEST on d 32 (31.3, 42.2, and 38.4%, respectively) and d 60 after AI (28.9, 37.2, and 33.9%, respectively), indicating that progesterone supplementation reestablished fertility in cows lacking a CL similar to that of cows in diestrus at the initiation of the timed AI program. Treatment did not affect pregnancy loss between d 32 and 60 of gestation. Pregnancy from a subset of cows with plasma progesterone concentrations indicated that a minimum concentration of 2.0 ng/mL was needed to optimize fertility. A single ultrasound examination effectively identified a low-fertility cohort of cows based on the absence of CL at the first GnRH injection of the Ovsynch protocol. Supplementation with 2 CIDR inserts increased progesterone in plasma by an additional 1.85 ng/mL compared with CON, resulting in concentrations of 2.77 ng/mL during development of the ovulatory follicle, which restored fertility in dairy cows lacking CL to a level similar to that of cows in diestrus.
Publisher: American Dairy Science Association
Date: 09-2010
Abstract: Objectives were to develop a timed artificial insemination (TAI) resynchronization program to improve pregnancy per AI and to evaluate responses of circulating progesterone and pregnancy-associated glycoproteins in lactating cows. Cows (n=1,578) were presynchronized with 2 injections of PGF2alpha, given 14 d apart starting on d 45+/-3 postpartum, followed by Ovsynch [2 injections of GnRH 7 d before and 56 h after injection of PGF2alpha, TAI 16 h after second injection (d 0)]. The Resynch-treated cows received an intravaginal progesterone insert from d 18 to 25, GnRH on d 25, and pregnancy diagnosis on d 32, and nonpregnant cows received PGF2alpha., GnRH 56 h later, and TAI 16 h later (d 35). The control cows were diagnosed for pregnancy on d 32 and nonpregnant cows received GnRH, PGF2alpha 39 d after TAI, GnRH 56 h later, and TAI 16 h later (d 42). Pregnancy was reconfirmed on d 60 after AI. Ovarian structures were examined in a subset of cows at the time of GnRH and PGF2alpha injections. Blood s les for analyses of progesterone and pregnancy-associated glycoproteins were collected every 2 d from d 18 to 30 in 100 cows, and collection continued weekly to d 60 for pregnant cows (n=43). Preenrollment pregnancies per AI on d 32 did not differ for cows subsequently treated as Resynch (45.8%, n=814) and control (45.9%, n=764), and pregnancy losses on d 60 were 6.7 and 4.0%, respectively. Resynchronized service pregnancy per AI (36%, n=441 39.5%, n=412) and pregnancy losses (6.3 and 6.7%) did not differ for Resynch and control treatments, respectively. Days open for pregnant cows after 2 TAI were less for the Resynch treatment than for the control treatment (96.2+/-0.82 vs. 99.5+/-0.83 d). Cows in the Resynch treatment had more large follicles at the time of GnRH. The number of corpora lutea did not differ between treatments at the time of PGF2alpha. Plasma progesterone for pregnant cows was greater for Resynch cows than for control cows (18-60 d 6.6 vs. 5.3 ng/mL), and plasma concentrations of progesterone on d 18 were greater for pregnant cows than for nonpregnant cows (5.3 vs. 4.3 ng/mL). Plasma pregnancy-associated glycoproteins during pregnancy were lower for cows in the Resynch treatment compared with control cows on d 39 (2.8 vs. 4.1 ng/mL) and 46 (1.3 vs. 3.0 ng/mL). Cows pregnant on d 32 that lost pregnancy by d 60 (n=7) had lower plasma concentrations of pregnancy-associated glycoproteins on d 30 than cows that maintained pregnancy (n=36 2.9 vs. 5.0 ng/mL). Pregnancy-associated glycoproteins on d 30 (>0.33 ng/mL) were predictive of a positive d 32 pregnancy diagnosis (sensitivity=100% specificity=90.6%). In conclusion, Resynch and control protocols had comparable pregnancy per AI for first and second TAI services, but pregnancy occurred 3.2 d earlier in the Resynch group because inseminations in the Resynch treatment began 7 d before those in the control treatment. Administration of an intravaginal progesterone insert, or GnRH, or both increased progesterone during pregnancy. Dynamics of pregnancy-associated glycoproteins were indicative of pregnancy status and pregnancy loss.
Publisher: American Dairy Science Association
Date: 07-2017
Abstract: Our objectives were to determine the effects of an injectable formulation of calcitriol on mineral metabolism and immune function in postpartum Holstein cows that received an acidogenic diet prepartum to minimize hypocalcemia. In experiment 1, cows within 6 h of calving received calcitriol (0, 200, or 300 μg) to determine the dose needed to increase plasma concentrations of Ca 300 μg was sufficient to sustain Ca for at least 3 d. In experiment 2, multiparous cows were assigned randomly to receive only vehicle (control, n = 25) or 300 μg of calcitriol (n = 25) subcutaneously within the first 6 h after calving. Blood was s led before treatment and 12 h later, then daily until 15 d in milk (DIM), and analyzed for concentrations of ionized Ca (iCa), total Ca (tCa), total Mg (tMg), and total P (tP), metabolites, and hormones. Urine was s led in the first 7 DIM and analyzed for concentrations of tCa, tMg, and creatinine. Neutrophil function was evaluated in the first week postpartum. Dry matter intake and production performance were evaluated for the first 36 DIM. Calcitriol administration increased concentrations of calcitriol in plasma within 12 h of application from 51 to 427 pg/mL, which returned to baseline within 5 d. Concentrations of iCa and tCa increased 24 h after treatment with calcitriol. Concentrations of iCa (control = 1.08 vs. calcitriol = 1.20 mM), tCa (control = 2.23 vs. calcitriol = 2.33 mM), and tP (control = 1.47 vs. calcitriol = 1.81 mM) remained elevated in cows treated with calcitriol until 3, 5, and 7 DIM, respectively, whereas concentration of tMg (control = 0.76 vs. calcitriol = 0.67 mM) was less in calcitriol cows than control cows until 3 DIM. Concentrations of parathyroid hormone decreased in calcitriol cows compared with control cows (control = 441 vs. calcitriol = 336 pg/mL). Calcitriol tended to increase plasma concentrations of β-hydroxybutyrate and serotonin, but concentrations of glucose, nonesterified fatty acids, and C-telopeptide of type I collagen in plasma did not differ between treatments. Cows treated with calcitriol excreted more urinary tCa (control = 0.5 vs. calcitriol = 2.1 g/d) and tMg (control = 4.5 vs. calcitriol = 5.0 g/d) in the first 7 and 2 DIM, respectively, than control cows. Compared with control, calcitriol improved the proportion of neutrophils with oxidative burst (control = 31.9 vs. calcitriol = 40.6%), mean fluorescence intensity for oxidative burst (control = 90,900 vs. calcitriol = 99,746), and mean fluorescence intensity for phagocytosis (control = 23,887 vs. calcitriol = 28,080). Dry matter intake, yields of milk, and milk components did not differ between treatments. Administration of 300 μg of calcitriol at calving was safe and effective in increasing blood concentration of iCa and plasma concentrations of calcitriol, tCa, and tP for the first 6 d after treatment, and improved measures of innate immune function in early-lactation Holstein cows.
Publisher: Wiley
Date: 26-07-2010
DOI: 10.1111/J.1439-0531.2010.01664.X
Abstract: Increasing reproductive performance of post-partum lactating dairy cows is a multi-factorial challenge involving disciplines of production medicine, nutrition, physiology and herd management. Systems of programmed timed insemination have been fine-tuned to achieve pregnancy per artificial inseminations (AI) approximating 45%. Systems have optimized follicle development, integrated follicle development with timing of induced corpus luteum regression and fine-tuned sequential timing of induced ovulation and AI. Use of programmes for insemination have identified occurrence of anovulatory ovarian status, body condition, uterine health and seasonal summer stress as factors contributing to reduced herd fertility. Furthermore, programmes of timed insemination provide a platform to evaluate efficacy of nutritional and herd health systems targeted to the transition and post-partum periods. The homeorhetic periparturient period, as cows deal with decreases in dry matter intake, results in a negative energy balance and is associated with a period of immunosuppression. Cows that transition well will cycle earlier and have a greater risk of becoming pregnant earlier post-partum. The innate arms of the immune system (acute and adaptive) are suppressed during the periparturient period. Cows experiencing the sequential complex of disorders such as dystocia, puerperal metritis, metritis, endometritis and subclinical endometritis are subsequently less fertile. Targeted strategies of providing specific nutraceuticals that provide pro- and anti-inflammatory effects, such as polyunsaturated fatty acids (e.g., linoleic, eicosapentaenoic/docosahexaenoic, conjugated linoleic acid), sequential glycogenic and lipogenic enrichment of diets, and organic selenium appear to differentially regulate and improve the immune and reproductive systems to benefit an earlier restoration of ovarian activity and increased fertility.
Publisher: American Dairy Science Association
Date: 11-2013
Abstract: The objective was to determine the effect of exogenous progesterone (P4) in a timed artificial insemination (TAI) protocol initiated at 2 different times post-AI on pregnancies per AI (P/AI) in lactating dairy cows. Cows (n=1,982) in 5 dairy herds were assigned randomly at a nonpregnancy diagnosis 32 ± 3 d post-AI to 1 of 4 resynchronization (RES) treatments arranged in a 2 × 2 factorial design using the Ovsynch-56 (GnRH, 7d later PGF2α, 56 h later GnRH, 16 h later TAI) protocol. Treatments were as follows: cows initiating RES 32 ± 3 d after AI with no supplemental P4 (d 32 RES-CON n=516) same as d 32 RES-CON plus a controlled internal drug release (CIDR) insert containing P4 at the onset of Ovsynch-56 (d 32 RES-CIDR n=503) cows initiating RES 39 ± 3 d after AI (d 39 RES-CON n=494) and same as d 39 RES-CON plus a CIDR (d 39 RES-CIDR n=491). Cows were inseminated if observed in estrus before TAI. The P/AI was determined 32 and 60 d after TAI. In a subgroup of cows (n=1,152), blood s les were collected and ovarian structures examined by ultrasonography on the days of the first GnRH (G1) and PGF2α of Ovsynch-56. Percentage of cows with a corpus luteum (CL) at G1 was unaffected by timing of treatments, but percentage of cows with a CL at PGF2α was greater for d 32 than for d 39 cows (87.9 vs. 79.4%). In addition, percentage of cows with P4 ≥ 1 ng/mL at G1 was unaffected by timing of treatments, but was increased for d 32 compared with d 39 RES cows on the day of the PGF2α of the RES protocols (86.5 vs. 74.3%). Treatment did not affect ovulation to G1 or P/AI 32 d after RES TAI (d 32 RES-CON=30.1%, d 32 RES-CIDR=28.8%, d 39 RES-CON=27.5%, d 39 RES-CIDR=30.5%). A greater percentage of d 39 RES cows underwent premature luteolysis during the RES protocol compared with d 32 RES cows. An interaction was detected between day of RES initiation and CIDR treatment, in which the CIDR increased P/AI 60 d after TAI for d 39 (CON=23.7% vs. CIDR=28.0%), but not for d 32 (CON=26.9% and CIDR=24.2%) cows. Pregnancy loss was unaffected by treatment. In addition, cows had improved P/AI 60 d after TAI when they received a CIDR and did not have a CL (CON-CL=28.2%, CON-No CL=19.2%, CIDR-CL=27.0%, and CIDR-No CL=26.5%) or had P4 <1 ng/mL (CON-High P4=27.8%, CON-Low P4=15.0%, CIDR-High P4=25.0%, and CIDR-Low P4=29.4%) at G1, but not if a CL was present or P4 was ≥ 1 ng/mL at G1. In conclusion, addition of a CIDR insert to supplement P4 during the RES protocol increased P/AI for cows initiating RES 39 ± 3 d after AI but not 32 ± 3 d after AI.
Publisher: Elsevier BV
Date: 07-2009
DOI: 10.1016/J.ANIREPROSCI.2008.06.007
Abstract: Multiparous Holstein cows (n=717) from two dairy farms were blocked at calving by parity and previous lactation milk yield and, within each block, randomly assigned to one of two treatments: a diet containing no yeast culture (Control n=359) or 30 g/d of a culture of Saccharomyces cerevisiae (YC n=358) from 20 to 140 d postpartum. Only cows calving during months of heat stress, May-August were enrolled. Lameness score (1-5 scale) was evaluated at study enrollment and again at 100 d postpartum. The body condition score (BCS, 1-5 scale) was evaluated at calving, 28, 58 and 140 d postpartum. Cows received two injections of PGF(2alpha) at 37 and 51 d postpartum, and those observed in estrus were inseminated. Cows not in estrus were enrolled in a timed AI protocol at 65 d postpartum and inseminated at 75 d postpartum. Ovaries were examined by ultrasonography at 37 and 51 d postpartum to determine whether estrous cycling had been initiated by the presence of a corpus lutem (CL) in at least one of the two examinations. Pregnancy was diagnosed at 31, 38 and 66 d after the first AI and at 38 and 66 d after the second and third AI. Diet did not affect time of onset of estrous cycles postpartum, and 8.2% of the cows were anovular. Detection of estrus in the 7d after the second injection of PGF(2alpha) was similar for control and YC. For control and YC, conception rates 38 d after AI at first (30.8% and 31.4%), second (39.3% and 35.1%) and third (25.8% and 30.6%) inseminations, and pregnancy losses did not differ, which resulted in similar median days to pregnancy and proportion of pregnant cows at 140 d postpartum. Yeast culture did not affect incidence of lameness, but tended to reduce lameness score. Lame cows and anovular cows had lesser conception rates at first AI, and extended interval from calving to conception. A THI of 71 was identified as the critical point in which fertility was reduced in lactating dairy cows, although the sensitivity and specificity were minimal. Cows exposed to a THI>71 on the day of first AI had a 33% reduction in the rate of pregnancy resulting in extended interval to pregnancy. Feeding a yeast culture of S. cerevisiae had minor effects on lameness score, but no impact on reproduction of multiparous cows under heat stress.
Publisher: Elsevier BV
Date: 02-2008
Publisher: American Dairy Science Association
Date: 09-2016
Abstract: Linoleic acid is an essential dietary fatty acid (FA). However, how the supplementation of linoleic acid during uterine and early life may modify the FA profile and transcriptome regulation of the liver, and performance of preweaned dairy calves is unknown. Our objective was to evaluate the effect of supplementation of essential FA to Holstein calves during late uterine and early life on their hepatic FA profile and global gene expression at 30 d of age. During the last 8 wk of pregnancy, Holstein cattle (n=96) were fed either no fat supplement (control), a saturated FA supplement enriched with C18:0, or an unsaturated FA supplement enriched with linoleic acid. Male calves (n=40) born from these dams were fed a milk replacer (MR) with either low (LLA) or high linoleic acid (HLA) concentration as the sole feedstuff during the first 30 d. Liver biopsy was performed at 30 d of age, and microarray analysis was performed on 18 liver s les. Total concentration of FA in liver were greater in calves fed LLA compared with those fed HLA MR (8.2 vs. 7.1%), but plasma concentrations of total FA did not differ due to MR diets. The FA profiles of plasma and liver of calves were affected differently by the prepartum diets. Specifically, the FA profile in liver was affected moderately by the feeding of fat prepartum, but the profiles did not differ due to the type of FA fed prepartum. The type of MR fed during the first 30 d of life had major effects on both plasma and liver FA profiles, resembling the type of fat fed. Plasma and liver of calves fed LLA MR had greater percentage of medium-chain FA (C12:0 and C14:0), whereas plasma and liver from calves fed HLA MR had greater percentages of linoleic and α-linolenic acids. Dams fed fat or a specific type of FA modified the expression of some genes in liver of calves, particularly those genes involved in biological functions and pathways related to upregulation of lipid metabolism and downregulation of inflammatory responses. Feeding HLA instead of LLA MR modified the expression of hepatic genes, including genes predicted to decrease infections and to increase lipid utilization and protein synthesis. Research evaluating the effect of FA supplementation during uterine and neonatal life on the future productivity of the neonate is warranted.
Publisher: Oxford University Press (OUP)
Date: 13-05-2020
Abstract: Uterine infection is associated with infertility in women and dairy cows, even after the resolution of infection. However, the mechanisms causing this persistent infertility are unclear. Here, we hypothesized that induced endometritis in non-lactating dairy cows would reduce the developmental competence of oocytes. Non-lactating Holstein cows received an intrauterine infusion of endometrial pathogenic bacteria (Escherichia coli and Trueperella pyogenes n = 12) or vehicle control (n = 11) on day 2 of the estrous cycle. Bacterial infusion increased expression of endometrial inflammatory mediators, and a mucopurulent discharge in the vagina confirmed the establishment of endometritis. Oocytes were collected by transvaginal ultrasound-guided ovum pickup on days 2, 24, 45, and 66 following infusion and subjected to in vitro fertilization and embryo culture. Bacterial infusion resulted in fewer cleaved oocytes developing to morulae compared to vehicle-infused controls (30.7 versus 45.0%), with the greatest effect observed in oocytes collected on day 24. Development to morula was inversely correlated with endometrial expression of IL6 on day 6. The expression of genes associated with embryo quality did not differ significantly between morulae from bacteria-infused and control cows. Artificial insemination 130 days after intrauterine infusion resulted in normal, filamentous embryos that produced interferon tau 16 days after conception in both infusion groups. This model of experimentally induced uterine infection successfully resulted in endometritis and a reduction in the proportion of oocytes that developed to morulae following in vitro fertilization. In conclusion, endometritis reduced the capacity of oocytes to develop to morulae.
Publisher: American Dairy Science Association
Date: 04-2009
Abstract: The objectives were to evaluate the effects of source of fatty acids (FA) on embryo quality of dairy cows. A total of 154 Holstein cows were assigned randomly to 1 of 2 sources of FA supplemented at 2% of the dietary dry matter as calcium salts of either palm oil (PO) or linoleic and trans-octadecenoic acids (LTFA) from 25 d prepartum to 80 d in milk (DIM). Cows were presynchronized beginning at 30 +/- 3 DIM and then subjected to the Ovsynch protocol beginning on d 39 +/- 3 postpartum. Timed artificial insemination was performed 12 h after the final GnRH of the Ovsynch protocol with semen from a single sire of proven fertility. The uteri of cows were nonsurgically flushed at 5 d after artificial insemination for collection of embryos-oocytes. Ovaries were examined by ultrasonography throughout the synchronization protocol. Blood was s led and plasma was analyzed for concentrations of metabolites and hormones. The body condition score and yields of milk and milk components were measured throughout the first 90 DIM. Treatment did not affect concentrations of nonesterified FA, beta-hydroxybutyrate, glucose, and progesterone in plasma. Body condition was similar between treatments. Milk production was similar between treatments, but concentrations of fat in milk and yields of fat and 3.5% fat-corrected milk decreased in cows fed LTFA, whereas concentration of true protein increased. Source of dietary FA did not influence ovulatory responses, diameter of the ovulatory follicle, and diameter of the corpus luteum during synchronization. Embryo-oocyte recovery relative to the number of corpora lutea did not differ between treatments. Fertilization tended to increase in cows fed LTFA compared with cows fed PO. Feeding LTFA improved the proportion of excellent-, good-, and fair-quality embryos, and embryos from cows fed LTFA had a greater number of blastomeres than embryos from cows fed PO. Feeding a more unsaturated source of FA improved fertilization and embryo development in lactating dairy cows, despite similar indicators of metabolic status.
Publisher: American Dairy Science Association
Date: 04-2009
Abstract: Objectives were to determine the effects of intrauterine (i.u.) infusion of ceftiofur hydrochloride on uterine health and fertility of dairy cows already receiving PGF(2alpha) for estrous synchronization. Holstein cows at 44 +/- 3 d in milk (DIM) were blocked by parity and diagnosis of metritis in the first 14 DIM and of other illnesses and, within each block, randomly assigned to 1 of 2 treatments: a single i.u. infusion of 125 mg of ceftiofur hydrochloride at 44 +/- 3 DIM (ceftiofur, n = 396), or no i.u. infusion (control, n = 416). All cows received 25 mg of PGF(2alpha) at 37 +/- 3 and 51 +/- 3 DIM as part of an estrous synchronization protocol. A subset of 547 cows was evaluated for clinical endometritis immediately before treatment, and 202 cows had an aseptic uterine s le collected before the injection of PGF(2alpha) at 51 +/- 3 DIM for bacteriology and diagnosis of subclinical endometritis (> or =5% neutrophils). Pregnancy on d 38 +/- 3 and 180 +/- 7 after the first artificial insemination, pregnancy loss, and interval from calving to pregnancy in the first 300 DIM were evaluated. The proportions of cows diagnosed with clinical endometritis before treatment were similar between ceftiofur and control treatments. Intrauterine infusion with ceftiofur did not influence prevalence of subclinical endometritis and positive uterine culture 7 d after treatment however, it reduced the prevalence of positive uterine culture in cows with clinical endometritis (29.0 vs. 51.4%) and reduced the overall prevalence of Arcanobacterium pyogenes (1.0 vs. 7.6%) at 51 +/- 3 DIM. Cows with clinical endometritis had increased prevalence of A. pyogenes (10.3 vs. 1.5%), Escherichia coli (5.9 vs. 0.75%), and overall positive uterine culture (41.2 vs. 22.4%) however, cows with subclinical endometritis only had an increased prevalence of A. pyogenes (10.2 vs. 1.5%). Ceftiofur did not affect pregnancy per artificial insemination in all cows or in cows previously diagnosed with metritis or clinical endometritis. Interval to pregnancy was similar for control and ceftiofur cows. Intrauterine infusion of ceftiofur hydrochloride reduced the prevalence of uterine infection in cows with clinical endometritis, and the prevalence of A. pyogenes, but did not affect the prevalence of subclinical endometritis or fertility of dairy cows already receiving PGF(2alpha).
Publisher: Editora Scienza
Date: 28-10-2020
Publisher: American Dairy Science Association
Date: 08-2018
Abstract: Vitamin D signaling in response to pathogen-associated molecules contributes to activation of innate immune responses of bovine monocytes. We hypothesized that lipopolysaccharide (LPS) of bacteria associated with mastitis in dairy cows activates the vitamin D pathway in innate immune cells of the udder and that increasing availability of 25-hydroxyvitamin D
Publisher: American Dairy Science Association
Date: 07-2018
Abstract: The objectives were to determine the optimal feeding amount of choline in a ruminally protected form to reduce the triacylglycerol (TAG) concentration in liver and to increase TAG in blood plasma of dairy cows. Pregnant, nonlactating multiparous Holstein cows (n = 77) were blocked by body condition score (3.59 ± 0.33) and assigned to treatment at 64 ± 10 d before calculated calving date. Dietary treatments were top-dressing of 0, 30, 60, 90, or 120 g/d of ruminally protected choline (RPC Balchem Corp., New H ton, NY) ions to supply the equivalent of 0, 6.5, 12.9, 19.4, and 25.8 g/d of choline ions. Diets were formulated to exceed nutrient requirements for maintenance and pregnancy and fed in ad libitum amounts for the first 5 d. From d 6 to 15, cows were restricted to consume approximately 31% of their net energy requirements to simulate early lactating cows in negative energy balance. Methionine intake was maintained throughout each 15-d period. Liver was biopsied at 5 and 14 d and analyzed for TAG and glycogen. Blood was s led on d 5 and 14 and plasma analyzed for glucose, insulin, cholesterol, β-hydroxybutyrate, long-chain fatty acids, and haptoglobin. On d 14, a mixture of saturated long-chain fatty acids, ground corn, and dried molasses (50:37:13) was offered (908 g, as-is basis) 10 h after the single daily feeding. Blood s les were collected for 19 h and plasma analyzed for TAG and cholesterol to assess apparent absorption of dietary fat. Mean dry matter intake and energy balance decreased from means of 9.5 to 3.3 kg/d and from 0.6 to -9.2 Mcal of net energy for lactation/d during the ad libitum and restricted feeding periods, respectively. Plasma concentrations of the lipid-soluble choline biomolecules, namely total phosphatidylcholines, total lysophosphatidylcholines, and sphingomyelin, increased with choline supplementation. Feed restriction increased plasma concentrations of β-hydroxybutyrate and free long-chain fatty acids, whereas those of glucose, insulin, and total cholesterol decreased. During feed restriction, concentration of hepatic TAG and plasma haptoglobin decreased linearly, whereas concentration of hepatic glycogen tended to increase quadratically with increasing intake of RPC. After fat supplementation, mean plasma concentration of TAG increased by an average of 21% with intake of RPC ions, peaking at intakes of ≥6.5 g/d of RPC ion. In summary, feeding RPC ions to cows in negative energy balance had increasing lipotropic effects on the liver when consumed up to 25.8 g/d, whereas feeding only 6.5 g/d increased concentrations of hepatic glycogen and TAG in the blood.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.THERIOGENOLOGY.2019.03.019
Abstract: The objectives were the determine the effects of presynchronization with PGF
Publisher: American Dairy Science Association
Date: 07-2020
Publisher: American Dairy Science Association
Date: 03-2023
Publisher: Elsevier BV
Date: 09-2011
DOI: 10.1016/J.ANIREPROSCI.2011.06.011
Abstract: The objectives of the current study were to evaluate the associations among reproductive performance of Holstein cows, single nucleotide polymorphism (SNP) in the R4C locus of the Exon-2 region of the leptin gene and health disorders. Lactating dairy cows (n=814) had their DNA sequenced at the Exon-2 region of the leptin gene to determine the presence of SNP in the R4C locus. Cows had the stage of estrous cycle synchronized with two injections of PGF(2α) 14d apart, with or without a progesterone insert. After the second PGF(2α), cows were either inseminated on detected estrus and, if not inseminated within 13d, cows were submitted to a timed artificial insemination (AI) protocol 13d after the second PGF(2α). Blood was s led at 35±3, 49±3, and 62±3d in milk (DIM) and cows with progesterone <1.0ng/mL in the first two s les were considered to be anovular, whereas those with at least one of the first two s les with progesterone ≥1.0ng/mL were considered to have initiated estrous cyclicity. Anovular cows with progesterone ≥1.0ng/mL at 62±3DIM were considered to have resumed estrous cyclicity. Pregnancy was diagnosed at 31 and 60d after first postpartum AI and at 42d after subsequent inseminations. Resulting genotypes were CC (34.6%), CT (48.2%), and TT (17.2%). Leptin genotype was associated (P=0.03) with increased prevalence of estrous cyclic cows at 49±3DIM, as TT cows were and tended to be less likely to be estrous cyclic than CC and CT cows, respectively. Other measures of reproductive performance in the first 305DIM were not associated with leptin genotype. Cows diagnosed with at least one postparturient disease were less likely to become pregnant after first (P<0.01) and second (P=0.02) AI and to be pregnant at 305DIM (P<0.01). Furthermore, cows diagnosed with a disease event had a 36% reduction (P<0.001) in the rate of pregnancy, which extended the median interval to pregnancy by 60d. Estrous cyclic cows had a 35% increased rate of pregnancy, which reduced the interval to pregnancy by 34d. Cows homozygous for the T allele were less likely to be cyclic early postpartum, but leptin genotype was not associated with other reproductive responses when cows were subjected to a controlled breeding program.
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.ANIREPROSCI.2008.01.014
Abstract: The objectives of this study were to evaluate factors associated with resumption of postpartum estrous cycles and embryonic survival in lactating dairy cows. Holstein cows, 6396 from four dairy farms were evaluated to determine the relationships among parity, body condition score (BCS) at calving and at AI, season of year when cows calved, and milk yield on resumption of postpartum estrous cycles by 65 days postpartum, and all the previous variables, estrual or anestrus and AI protocol on conception rates and embryonic survival at the first postpartum insemination. Cows had their estrous cycle pre-synchronized with two PGF(2alpha) injections given 14 days apart and were inseminated between 69 and 82 days postpartum following either an estrous or ovulation synchronization protocol initiated 12-14 days after the presynchronization. Blood was s led and analyzed for progesterone twice, 12-14 days apart, to determine whether cows had initiated onset of estrous cycles after calving. Cows were scored for body condition in the week after calving, and again at AI, between 69 and 82 days postpartum. Pregnancy was diagnosed at 30+/-3 and 58+/-3 days after AI. Farm influenced all reproductive outcomes evaluated. More (P<0.0001) multiparous than primiparous cows had initiated estrous cycles. Onset of estrous cycles was also influenced (P<0.01) by BCS at calving and at AI, BCS change, season, and milk yield. More (P<0.001) cows that had initiated estrous cycles than anestrous cows were pregnant at 30 and 58 days after AI, but anestrus did not affect pregnancy loss. Conception rates were also influenced (P<0.01) by parity, BCS at calving and AI, BCS change, and season however, milk yield and insemination protocol were not associated with conception rates at 30 and 58 days after AI. Factors that reduced conception rate on day 30 after AI also increased pregnancy loss between 30 and 58 days of gestation. Improving BCS at calving and AI, minimizing losses of BCS after calving, and hastening onset of estrous cycles early postpartum are all expected to increase conception because of enhanced embryonic survival.
Publisher: American Dairy Science Association
Date: 04-2004
Publisher: Bioscientifica
Date: 03-2011
DOI: 10.1530/REP-10-0375
Abstract: Fertility of lactating dairy cows is associated with reduced progesterone (P 4 ) concentration compared with nonlactating animals. The objective of the current study was to determine whether P 4 during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P 4 (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400 mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F 2α (PGF 2α ) injections given with the ninth and tenth injections of FSH, GNRH given 48 h after the first PGF 2α injection, and timed insemination 12 and 24 h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P 4 inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was s led daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P 4 was ( P .01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos–oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was ( P =0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not ( P ≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P 4 during follicle growth.
Publisher: Wiley
Date: 30-08-2011
Publisher: American Dairy Science Association
Date: 05-2002
DOI: 10.3168/JDS.S0022-0302(02)74178-7
Abstract: Our objectives were to evaluate the effect of left displacement of abomasum (LDA) after correction by toggle-pin suture (TPS) on lactation performance, reproduction and health in Holstein dairy cows in a commercial dairy farm. Cows diagnosed with LDA and corrected by the TPS procedure (188 cows) during the first 70 d postpartum were matched with control herd-mates (186 controls) according to lactation number, calving date, and previous lactation 305-d mature equivalent milk yield. Cows were grouped according to parity and days in milk and fed the same total mixed ration throughout a 321-d lactation. Data collected included yields of milk and 3.5% fat-corrected milk (FCM), concentration and yields of milk fat, somatic cell count, incidence of mastitis, abortion, death and culling, in addition to reproductive measures. Cows affected with LDA corrected by the TPS procedure produced less milk and tended to produce less 3.5% FCM than control cows, but the decrease in production occurred only during the first 4 mo of lactation. Left displacement of abomasum did not affect the interval from calving to conception and conception rates, but it extended the period from calving to first postpartum artificial insemination. Incidences of abortions and mastitis were not influenced by LDA. Cows affected with LDA remained in the study for a shorter period than their control herdmates, and higher proportions of cows with LDA were sold or died. Death and culling were more pronounced immediately after the diagnosis of LDA and the TPS procedure.
Publisher: American Dairy Science Association
Date: 04-1999
Publisher: Wiley
Date: 30-08-2011
Publisher: Elsevier BV
Date: 07-2008
DOI: 10.1016/J.THERIOGENOLOGY.2008.03.015
Abstract: The objectives were to evaluate the accuracy of detecting a functional CL by transrectal palpation and ultrasonography, and to optimize the accuracy of detecting a functional CL by ultrasonography in Holstein cows. In Experiment 1, four veterinarians performed transrectal palpation in 1250 cows at 37 d in milk (DIM), two veterinarians repeated transrectal palpation in 823 cows at 58 DIM, and one veterinarian performed 206 ultrasonographic examinations at 37 DIM. In Experiment 2, 987 and 983 ultrasonographic examinations were performed at 21 and 24 d after AI by one veterinarian for detection and measurement of CL. Cows with a blood progesterone concentration > or =1ng/mL were assumed to have a functional CL. Sensitivity and specificity were optimized using receiver operating characteristic analysis. In Experiment 1, sensitivity of transrectal palpation for diagnosing a functional CL ranged from 33.3 to 59.9% at 37 DIM and from 48.3 to 68.4% at 58 DIM, whereas specificity ranged from 76.7 to 93.2% at 37 DIM and from 73.3 to 86.7% at 58 DIM. Sensitivity and specificity for ultrasonography were 89.4 and 45.7%, respectively. In Experiment 2, the sensitivity and specificity of ultrasonography were 97.3 and 38.1% at 21 d after AI, and were 97.9 and 51.0% at 24 d after AI. Sensitivity and specificity were optimized using a cutoff diameter of 23mm at 21 d and 22mm at 24 d, which resulted in sensitivity and specificity of 87.2 and 83.0% at 21 d, and 89.5 and 89.4% at 24 d after AI, respectively. Sensitivity was low and specificity was high for transrectal palpation, whereas ultrasonography resulted in high sensitivity and low specificity. Using a cutoff diameter during ultrasonography improved accuracy of detection of a functional CL compared with either ultrasonography without cutoff or transrectal palpation.
Publisher: American Dairy Science Association
Date: 08-2014
Abstract: The objectives of the current study were to evaluate the effects of supplemental progesterone after artificial insemination (AI) on expression of IFN-stimulated genes (ISG) in blood leukocytes and fertility in lactating dairy cows. Weekly cohorts of Holstein cows were blocked by parity (575 primiparous and 923 multiparous) and method of insemination (timed AI or AI on estrus) and allocated randomly within each block to untreated controls, a controlled internal drug release (CIDR) containing 1.38g of progesterone from d 4 to 18 after AI (CIDR4), or a CIDR on d 4 and another on d 7 after AI and both removed on d 18 (CIDR4+7). Blood was s led to quantify progesterone concentrations in plasma and mRNA expression in leukocytes for the ubiquitin-like IFN-stimulated gene 15-kDa protein (ISG15) and receptor transporter protein-4 (RTP4) genes. Pregnancy was diagnosed on d 34±3 and 62±3 after AI. Treatment increased progesterone concentrations between d 5 and 18 after AI in a dose-dependent manner (control=3.42, CIDR4=4.97, and CIDR4+7=5.46ng/mL). Cows supplemented with progesterone tended to have increased luteolysis by d 19 after AI (control=17.2 CIDR4=29.1 CIDR4+7=30.2%), which resulted in a shorter AI interval for those reinseminated after study d 18. Pregnancy upregulated expression of ISG in leukocytes on d 19 of gestation, but supplementing progesterone did not increase mRNA abundance for ISG15 and RTP4 on d 16 after insemination and tended to reduce mRNA expression on d 19 after AI. For RTP4 on d 19, the negative effect of supplemental progesterone was observed only in the nonpregnant cows. No overall effect of treatment was observed on pregnancy per AI on d 62 after insemination and averaged 28.6, 32.7, and 29.5% for control, CIDR4, and CIDR4+7, respectively. Interestingly, an interaction between level of supplemental progesterone and method of AI was observed for pregnancy per AI. For cows receiving exogenous progesterone, the lower supplementation with CIDR4 increased pregnancy per AI on d 62 in cows inseminated following timed AI (CIDR4=39.2 CIDR4+7=27.5%) in those inseminated following detection of estrus, however, the use of a second insert on d 7 resulted in greater pregnancy per AI (CIDR4=26.9 CIDR4+7=31.5%). Pregnancy loss did not differ among treatments. Supplemental progesterone post-AI using a single intravaginal insert on d 4 was beneficial to pregnancy in cows inseminated following timed AI, but incremental progesterone with a second insert on d 7 did not improve fertility of dairy cows.
Publisher: American Dairy Science Association
Date: 08-2010
Abstract: Two experiments evaluated the influence of follicular wave at artificial insemination (AI) on fertility of dairy cows. In experiment 1, data from 5,607 lactating cows enrolled in estrous and ovulation synchronization programs for AI were evaluated. Cows' blood was analyzed for progesterone 7 to 14 d apart, with the second s le collected on the day of the first GnRH (GnRH1) of the synchronization protocol. Cows were classified as cyclic if progesterone was >or=1 ng/mL in at least 1 of the 2 s les and as anovular if both s les were <1 ng/mL. Cyclic cows were categorized as low (CLOW or= 1 ng/mL) progesterone on the day of GnRH1, which would result in ovulation of the dominant follicle of the first (FW) and second (SW) follicular waves, respectively, at AI. Pregnancy per AI (P/AI) was determined 30 and 53 d after AI. In experiment 2, 220 cyclic Holstein cows received 2 injections of PGF(2alpha) administered 14 d apart. The Ovsynch protocol (d 0 GnRH, d 7 PGF(2alpha), d 9 GnRH, d 9.5 timed AI) was initiated either 3 or 10 d after the second PGF(2alpha) of the presynchronization to result in insemination to the FW or SW dominant follicles. Blood was analyzed for progesterone and ovaries were scanned to determine ovulatory responses and follicle diameter. Pregnancy was determined on d 32 and 67 after timed AI. In experiment 1, P/AI on d 30 was greater for CHIGH cows than for CLOW and anovular cows (43.0, 31.3, and 29.7%, respectively), but because of pregnancy loss, P/AI on d 53 was lowest for anovular cows. Proportions of cows with short reinsemination intervals differed among groups and were 7.1, 15.7, and 11.9% for CHIGH, CLOW, and anovular cows, respectively. Pregnancy loss was greater for anovular cows than for CLOW cows (15.0 vs. 10.0%) and was intermediate for CHIGH cows (13.5%). In experiment 2, 9.8 and 97.2% of the FW and SW cows, respectively, had progesterone >or=1 ng/mL at GnRH1. Concentrations of progesterone at the GnRH1 and PGF(2alpha) injections of the Ovsynch protocol were greater for SW cows than FW cows. Pregnancy per AI was greater for SW cows than for FW cows (41.7 vs. 30.4%) despite less ovulation to GnRH1 in SW cows than in FW cows (78.7 vs. 88.4%). Collectively, these data indicate that follicular wave of the ovulatory follicle and not cyclic status caused the greatest reduction in P/AI in dairy cows. Whether the culprit is the follicle itself or the hormonal milieu characteristic of the first follicular wave and the early stage of the estrous cycle remains to be elucidated. Synchronization programs that induced ovulation of the FW follicle at AI reduced P/AI in lactating dairy cows, and ovulation of the FW follicle, or development of the ovulatory follicle under low progesterone concentrations, or both, might be mechanisms for reduced fertility in anovular cows.
Publisher: Elsevier BV
Date: 12-2011
Publisher: American Dairy Science Association
Date: 10-2011
Abstract: Objectives were to compare the effect of presynchronization and resynchronization methods on fertility responses of grazing dairy cows at first and second artificial insemination (AI) and pregnancy rate during the entire breeding season. Lactating dairy cows (n = 1,263) in 2 seasonal grazing farms were blocked, within farm, by parity, breed and days in milk. Within each block, cows were randomly assigned to 1 of 4 treatments arranged as a 2 × 2 factorial with 2 presynchronization and 2 resynchronization treatments. Cows had their estrous cycles presynchronized with either a PGF(2α)-based program (Presynch) consisting of 2 injections of PGF(2α) administered 14 d apart and starting the timed AI protocol 11 d later, or with a PGF(2α)-GnRH-based presynchronization program (G6G) consisting of an injection of PGF(2α), followed 3 d later by an injection of GnRH and starting the timed AI protocol 6 d later. All cows received the first insemination on the same day, which was considered study d 0 and also d 0 of the breeding season. All cows received the 5-d timed AI protocol that consisted of GnRH on d -8, PGF(2α) on d -3 and -2, and GnRH+timed AI on d 0. Blood was s led and analyzed for progesterone on d -8. On d 12, cows in each presynchronization treatment either remained as untreated controls (RCON) or received a controlled internal drug-release (CIDR) insert containing progesterone for 7 d (RCIDR). Estrus was observed daily starting on d 19 and cows in estrus were inseminated on the same day. On d 35, bulls were placed with the cows for an additional 65 d, completing a 100-d breeding season. Holstein cows were less likely to have progesterone ≥ 1 ng/mL on d -8, and had less expression of estrus and pregnancy per AI (P/AI), which resulted in a slower rate of pregnancy and a smaller proportion of pregnancy at the end of the study than did Jersey or crossbred cows. In addition, body condition, days in milk, and plasma progesterone concentration at the first GnRH injection of the timed AI protocol had marked effects on the reproductive performance of lactating grazing dairy cows. A greater proportion of G6G cows had progesterone ≥ 1 ng/mL at the first GnRH injection of the timed AI protocol compared with Presynch cows (82.0 vs. 74.3%). Presynchronization treatment did not influence P/AI, but cows in G6G had increased risk of pregnancy loss between d 30 and 65 after the first AI (12.9 vs. 8.1%). Nevertheless, an interaction between presynchronization and ovarian status was observed, and cows initiating the timed AI with progesterone ≥ 1 ng/mL had greater P/AI when previously treated with Presynch than G6G. On the other hand, G6G benefited P/AI of cows initiating the timed AI with progesterone < 1 ng/mL. Resynchronization with RCIDR altered the pattern of return to estrus, but it did not increase the rate of re-insemination and decreased the proportion of pregnant cows at the end of the 100-d breeding period (80.6 vs. 84.4%).
Publisher: American Dairy Science Association
Date: 08-2004
Publisher: Oxford University Press (OUP)
Date: 04-11-2022
DOI: 10.1093/JAS/SKAC366
Abstract: Bos taurus × Bos indicus crosses are widespread in tropical and subtropical regions, nonetheless, quantitative information about the influence of B. indicus genetics on the reproductive performance of beef cattle is lacking. Herein, we determined the association between level of B. indicus genetics and reproduction from a 31-yr dataset comprising sequential breeding seasons of the University of Florida multibreed herd (n = 6,503 Angus × Brahman cows). The proportion of B. indicus genetics in this herd is evenly distributed by each 1/32nd or approximately 3-percentage points. From 1989 to 2020, the estrous cycle of cows was synchronized for artificial insemination (AI) based on detected estrus or timed-AI (TAI) using programs based on gonadotropin-releasing hormone and prostaglandin, and progestin rogesterone. All cows were exposed to natural service after AI and approximately 90-d breeding seasons, considering the day of AI as day 0. The proportion of B. indicus genetics of cows was associated negatively with pregnancy per AI, ranging from 51.6% for cows with 0%–19% of B. indicus genetics to 37.4% for cows with 81%–100% of B. indicus genetics. Similar association was found for estrous response at the end of the synchronization protocol, ranging from 66.3% to 38.4%, respectively. This reduced estrous response helped to explain the pregnancy results, once the pregnancy to AI of cows showing estrus was 2.3-fold greater than for those not showing estrus and submitted to TAI. Despite reduced pregnancy per AI, the increase in the proportion of B. indicus genetics of cows was not associated with a reduction in the proportion of pregnant cows at the end of the breeding season. Nevertheless, the interval from entering the breeding season to pregnancy was lengthened as the proportion of B. indicus genetics of cows increased. The median days to pregnancy was extended by 25 when the proportion of B. indicus genetics surpassed 78% compared with less than 20%. Thus, the increase in the proportion of B. indicus genetics of cows was related to a reduction in pregnancy per AI and lengthening the interval to attain pregnancy during the breeding season, but not with the final proportion of pregnant cows. As a result, reproductive management strategies directed specifically to cows with a greater proportion of B. indicus genetics are needed to improve the rate of pregnancy in beef herds.
Publisher: American Dairy Science Association
Date: 04-2010
Abstract: The objectives of this study were to evaluate the effect of administering 500 mg of recombinant bovine somatotropin (bST) every 10 d on ovulatory responses, estrous behavior, and fertility of lactating Holstein cows. Lactating dairy cows were assigned to 1 of 2 treatments: a control with no administration of bST (73 primiparous and 120 multiparous cows) or 6 consecutive administrations of 500 mg of bST (83 primiparous and 123 multiparous cows) given subcutaneously at 10-d intervals starting 61+/-3 d postpartum (study d 0), concurrent with the initiation of the timed artificial insemination (AI). Blood s les were collected thrice weekly from 61+/-3 to 124+/-3 d in milk (DIM), and plasma s les were analyzed for concentrations of estradiol, glucose, insulin, insulin-like growth factor 1, and progesterone. The estrous cycle of cows was presynchronized with 2 injections of PGF(2alpha) at 37+/-3 and 51+/-3 DIM, and the Ovsynch timed AI protocol was initiated at 61+/-3 DIM. Ovaries were scanned to determine ovulatory responses during the Ovsynch protocol. Pregnancy was diagnosed at 33 and 66 d after AI. Body condition was scored on study d 0, 10, 42, and 76. Sixty-four cows were fitted with a pressure mounting sensor with radiotelemetric transmitters to monitor estrous behavior. Treatment of lactating dairy cows with 500 mg of bST at 10-d intervals increased yields of milk and milk components in the first 2 mo after treatment. Body condition of bST-treated cows remained unaltered, whereas control cows gained BCS. Treatment with bST increased concentrations of insulin-like growth factor 1 chronically, but concentrations of insulin and glucose increased only transiently in the first 7 d after the first injection of bST. Concentrations of progesterone during and after the Ovsynch protocol remained unaltered after treatment with bST likewise, ovulatory responses during the Ovsynch protocol were mostly unaltered by treatment. Concentration of estradiol tended to be greater for bST cows than for control cows immediately before induction of ovulation in the Ovsynch protocol. Similarly, the mean and the peak concentrations of estradiol were greater for bST cows than for control cows when monitored during spontaneous estrus. Nevertheless, duration of estrus and the median number of standing events were less for bST cows than for control cows. Pregnancies per AI after the first and second postpartum inseminations were not affected by bST treatment. Treatment of lactating dairy cows with 500 mg of bST every 10 d improved lactation performance, but it did not affect pregnancies per AI and it reduced expression of estrus.
Publisher: The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS
Date: 2014
DOI: 10.3906/VET-1407-29
Location: Brazil
No related grants have been discovered for José Eduardo Santos.