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0000-0003-1097-7280
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Universidade Federal de Goiás
,
University of California Davis
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Publications
Parameter estimation and sensitivity analysis of fat deposition models in beef steers using acslXtreme
Publisher: Elsevier BV
Date: 05-2009
Effects of cimaterol on energy utilization for maintenance and for protein and fat deposition by wether and ewe lambs given chopped lucerne hay or lucerne-barley pellets
Publisher: Cambridge University Press (CUP)
Date: 02-1990
DOI: 10.1017/S0003356100004530
Abstract: The effects of sex (wethers v. ewes), diet (chopped lucerne hay v. lucerne-barley pellets) and cimaterol on energy utilization by Suffolk cross lambs were determined by comparative slaughter. Quadratic regression of energy retention (RE) on metabolizable energy intake (MEI) enabled estimation of maintenance energy requirements (E m ), efficiencies of gain (k total ) and maximum rates of gain (RE MAX ). Regressions using RE in fat and protein v. MEI yielded analogous parameters for fat and protein deposition (E m fat , k fat , RE MAX fat and E mprotcin , k prolein , RE MAXprotcin respectively). E m was lower in wethers than ewes (455 v. 510 kJ/kg M 0·75 per day respectively), but was unaffected by diet or cimaterol. Sex and cimaterol did not affect ktotai. which was higher in lambs given pellets compared with lambs given hay (0·417 v. 0·224 respectively). Similarly, RE MAX was higher in lambs given pellets than in lambs given hay (326 v. 114 kJ/kg 0·75 per day respectively). None of the groups differed significantly in the parameters of fat deposition, which averaged 480 kJ/kg 0·75 per day for E m fal, 0·224 for ktat, and 250 kJ/kg M 0·75 per day for RE MAX, fat- E m.protein was lower in wethers than in ewes (466 v. 569 kJ/kg 0·075 per day, respectively), and was further reduced by cimaterol (418 and 507 kJ/kg 0·75 per day for wethers and ewes respectively). Estimates of kprotcin were higher in wethers than in ewes (0·091 v. 0·064 respectively), and were increased by cimaterol (0·115 and 0·089 for wethers and ewes respectively). Similarly REMAX protein was higher in wethers than in ewes (47 v. 37 kJ/kg 0·75 per day respectively), and was increased by cimaterol (58 and 48 kJ/kg 0·75 per day for wethers and ewes respectively). The repartitioning action of cimaterol was additive with effects of diet, intake and sex.
Total tract and rumen digestibility of mulberry foliage (Morus alba), alfalfa hay and oat hay in sheep
Publisher: Elsevier BV
Date: 11-2007
Evidence of increased substrate availability to in vitro-derived bovine foetuses and association with accelerated conceptus growth
Publisher: Bioscientifica
Date: 09-2004
DOI: 10.1530/REP.1.00188
Abstract: Changes in placental development have been associated with foetal abnormalities after in vitro embryo manipulations. This study was designed to investigate bovine conceptus development and substrate levels in plasma and fluids in in vivo - and in vitro -produced (IVP) concepti and neonates. In vivo -produced and IVP embryos were derived by established embryo production procedures. Pregnant animals from both groups were slaughtered on days 90 or 180 of gestation, or allowed to go to term. Conceptus and neonatal physical traits were recorded foetal, maternal and neonatal blood, and foetal fluids were collected for the determination of blood and fluid chemistry, and glucose, fructose and lactate concentrations. Placental transcripts for specific glucose transporters were determined by quantitative RT-PCR. No significant differences in uterine and conceptus traits were observed between groups on day 90. On day 180, larger uterine, placental and foetal weights, and an increase in placental gross surface area (SA) in IVP pregnancies were associated with increased glucose and fructose accumulation in foetal plasma and associated fluids, with no differences in the expression of components of the glucose transporter system. Therefore, the enlarged placental SA in IVP pregnancies suggests an increase in substrate uptake and transport capacity. Newborn IVP calves displayed higher birth weights and plasma fructose concentrations soon after birth, findings which appeared to be associated with clinical and metabolic distress. Our results indicated larger concepti and increased placental fructogenic capacity in mid- to late IVP pregnancies, features which appeared to be associated with an enhanced substrate supply, potentially glucose, to the conceptus.
Relationships among dietary protein, feed intake and tissue protein turnover in lactating rats
Publisher: Elsevier BV
Date: 09-1986
Abstract: Effects of protein and energy intake on tissue protein synthesis and degradation were studied in rats fed 12, 24 and 36% protein diets at 100, 70, 50 and 30% of ad libitum intake begining on d 7 of lactation. Rates of protein synthesis were measured in liver, mammary, abdominal viscera and remaining carcass of rats on d 10 of lactation. Tissue protein loss was estimated as the difference in tissue protein from d 7 to 14. Data were analyzed using stepwise multiple quadratic regression to define response surfaces of protein loss, synthesis and degradation to intake of protein and energy. Protein loss increased with restriction of energy and protein intake in all tissues. However, carcass protein synthesis and degradation did not vary systematically with either energy or protein intake. Energy intake restriction increased visceral protein turnover while protein intake restriction decreased rate of protein turnover. Liver protein loss increased with decreased dietary protein due to increased liver protein degradation. Decreased energy intake also increased liver protein loss without directly affecting rate of synthesis or degradation. Mammary protein synthesis decreased very slightly with energy restriction while decreased protein intake sharply inhibited protein synthesis.
Growth of total fat and lean and of primal cuts is affected by the sex type
Publisher: Elsevier BV
Date: 2017
Note on the comparison of calpains I, II and calpastatin activity in two different types of porcine skeletal muscles
Publisher: Elsevier BV
Date: 06-1993
DOI: 10.1016/0300-9629(93)90201-E
Abstract: 1. Activities of calpains I and II and calpastatin in two different types of porcine skeletal muscles were compared. 2. Semimembranosus muscle was composed of mixed fiber types with mainly glycolytic fibers (65%), while masseter muscle was composed exclusively of oxidative fibers. 3. Calpain I activity was lower and calpain II activity was higher in masseter muscle as compared to semimembranosus muscle. Calpastatin activities were similar in both muscles.
Interrelationships between sex and ractopamine on protein and lipid deposition in rapidly growing pigs.
Publisher: Oxford University Press (OUP)
Date: 11-1993
Abstract: Sixty pigs were used to investigate the effects of two levels of dietary ractopamine (RAC 0 and 20 mg/kg) and three sex types (SEX boars, gilts, and barrows) on performance over the live weight range 60 to 90 kg. Pigs were housed in in idual pens and allowed ad libitum access to a diet containing 3.466 Mcal of DE and 10.7 g of lysine/kg. Control boars exhibited faster and more efficient growth and deposited more protein and less fat than gilts or barrows. The RAC increased ADG by 17 and 21% in gilts and barrows but not in boars. Feed intake was not altered by dietary RAC. Dietary RAC increased the rate of protein deposition by 15, 42, and 41% in boars, gilts, and barrows, respectively. Nevertheless, the daily rate of protein deposition was greatest in RAC-treated boars. The RAC tended to reduce the daily rate of fat deposition by 21% in boars but not in gilts or barrows. Carcass protein content increased by 5% and fat content decreased by 8% in response to RAC. These improvements in carcass composition occurred without compromising meat quality. Results show that RAC is a potent stimulator of protein deposition in finishing pigs. However, increased protein deposition is not necessarily at the expense of fat deposition.
Development and evaluation of empirical equations to interconvert between twelfth-rib fat and kidney, pelvic, and heart fat respective fat weights and to predict initial conditions of fat deposition models for beef cattle
Publisher: Oxford University Press (OUP)
Date: 08-2008
Abstract: The Davis growth model (DGM) simulates growth and body composition of beef cattle and predicts development of 4 fat depots. Model development and evaluation require quantitative data on fat weights, but sometimes it is necessary to use carcass data that are more commonly reported. Regression equations were developed based on published data to interconvert between carcass characteristics and kilograms of fat in various depots and to predict the initial conditions for the DGM. Equations include those evaluating the relationship between the following: subcutaneous fat (SUB, kg) and 12th-rib fat thickness (mm) visceral fat (VIS, kg) and KPH (kg) DNA (g) in intermuscular, intramuscular, subcutaneous, and visceral fat depots and empty body weight and contributions of fat (kg) in intramuscular (INTRA), SUB, and VIS fat depots and total body fat (kg). The intermuscular fat (INTER, kg) contribution was found by difference. The linear regression equations were as follows: SUB vs. 12th-rib fat thickness (n = 75 P < 0.01) with R(2) = 0.88 and SE = 10.00 VIS vs. KPH (kg n = 78 P < 0.01) with R(2) = 0.95 and SE = 2.82 the DNA (g) equations for INTER, INTRA, SUB, and VIS fat depots vs. empty body weight (n = 6, 5, 6, and 6 P = 0.08, P < 0.01, P < 0.01, and P = 0.05) with R(2) = 0.57, 0.93, 0.93, and 0.66, and SE = 0.03, 0.003, 0.02, and 0.03, respectively and initial contribution of INTRA, SUB, and VIS fat depots vs. total body fat (n = 23 P < 0.01) for each depot, with R(2) = 0.97, 0.99, and 0.97, and SE = 0.61, 0.93, and 1.41, respectively. All empirical equations except for DNA were challenged with independent data sets (n = 12 and 10 for SUB and VIS equations and n = 9 for the initial INTER, INTRA, SUB, and VIS fat depots). The mean biases were -2.21 (P = 0.12) and 2.11 (P < 0.01) kg for the SUB and VIS equations, respectively, and 0.05 (P = 0.97), -0.37 (P = 0.27), 1.82 (P = 0.08), and -1.50 (P = 0.06) kg for the initial contributions of INTER, INTRA, SUB, and VIS fat depots, respectively. The random components of the mean square error of prediction were 73 and 26% for the SUB and VIS equations, respectively, and similarly were 99, 85, 62, and 61% for the initial contributions of INTER, INTRA, SUB, and VIS fat depots, respectively. Both the SUB and VIS equations predicted accurately within the bounds of experimental error. The equations to predict initial fat contribution (kg) were considered adequate for initializing the fat depot differential equations for the DGM and other beef cattle simulation models.
Estimates of environmental effects and genetic parameters for body measurements and weight in Brahman cattle raised in Mexico
Publisher: Wiley
Date: 08-2002
Morphometric developmental pattern of bovine handmade cloned concepti in late pregnancy
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/RD15215
Abstract: Cloning procedures often interfere with conceptus growth and life ex utero, in a set of symptoms known as abnormal offspring syndrome (AOS). The aim of the present study was to compare the developmental pattern of in vivo-derived (IVD), IVF-derived and handmade cloning-derived (NT-HMC) Day 225 bovine concepti using established procedures. Pregnancy diagnosis was performed on Day 30 following blastocyst transfer on Day 7. Conceptus morphometry was assessed by ultrasonography on Day 51, and on Day 225 pregnant cows were killed for morphological examination of concepti. Pregnancy outcome was similar between groups, with greater pregnancy losses in the first trimester (70.6%) and smaller fetuses on Day 51 in the NT-HMC group than in the IVD (14.3%) and IVF (20.0%) groups. However, NT-HMC-derived concepti were twofold larger on Day 225 of gestation than controls. A higher frequency (63.5%) of placentomes larger than the largest in the IVD group was observed in the NT-HMC group, which may be relevant to placental function. Conceptus traits in the IVF group were similar to the IVD controls, with only slight changes in placentome types. Morphological changes in cloned concepti likely affected placental function and metabolism, disrupting the placental constraining mechanism on fetal growth in mid- to late pregnancy.
Bayesian estimates of genetic parameters for reproductive traits in Nellore cows raised on pasture in tropical regions
Publisher: Universidad de Antioquia
Date: 11-05-2016
Characterization of β1 - and β2 -adrenoceptors in rat skeletal muscles
Publisher: Elsevier BV
Date: 10-1991
DOI: 10.1016/0006-2952(91)90516-8
Abstract: Binding studies with (-)-[125I]cyanopindolol (ICYP) were conducted to characterize beta-adrenoceptors in plantaris and soleus muscles of rats (male, 250-300 g). The distribution of beta 1- and beta 2-adrenoceptors in different muscle fiber types, identified in serial sections by succinic dehydrogenase (SDH) staining, was studied by autoradiography. The densities of binding sites (Bmax, fmol/mg protein) were 5.4 +/- 0.9 (mean +/- SEM) in plantaris and 11.5 +/- 2.0 in soleus muscle. In plantaris muscle, monophasic competition curves were observed when binding experiments were performed using CGP20712A (50 pM to 0.5 mM), a beta 1-adrenoceptor selective antagonist, or ICI 118,551 (50 pM to 20 microM), a beta 2-adrenoceptor selective antagonist, to compete for ICYP binding. Analysis with LIGAND revealed a single binding site with a KD value of 2.41 +/- 0.56 nM (mean +/- SEM) for ICI 118,551 and 8.93 +/- 3.00 microM for CGP 20712A, indicating the presence of a homogeneous population of beta 2-adrenoceptors. In soleus muscle, competition curves were biphasic with 16-21% beta 1-adrenoceptors. Autoradiographic studies supported the findings from binding studies with membrane homogenates. The ICYP binding pattern was associated closely with the muscle fiber types identified by SDH staining. Propranolol-resistant binding sites were observed, and these sites were associated with muscle fibers positive to SDH staining.
Meta-analysis to predict sweating and respiration rates for Bos indicus, Bos taurus, and their crossbreds
Publisher: Oxford University Press (OUP)
Date: 12-2011
Abstract: The overall objective of this work was to develop empirical equations from a meta-analysis study to be used to implement initial values in a mechanistic heat balance model. The meta-analysis was conducted to 1) develop prediction equations for sweating and respiration rate (SR, g·m(-2)·h(-1) and RR, breaths·min(-1), respectively) based on skin and body temperature (T(s) and T(b), °C, respectively) for different breed types: Bos indicus, Bos taurus, and their crossbreds, and 2) evaluate the fit of existing SR equations and the SR and RR equations (from objective 1) against independent data sets. Fourteen studies were collected for the SR analysis, 12 for fitting and 2 for evaluation. The fitted SR equations (Thompson model) for the 3 breeds types were B. indicus, SR = 0.085e(0.22·T(s)) B. taurus, SR = 0.75e(0.15·T(s)) and crossbreds, SR = 0.015e(0.25·T(s)). Twenty-three studies were collected for the RR analysis, 20 for fitting and 3 for evaluation. The fitted RR equations for the 3 breed types were B. indicus, RR = -1,660 + 43.8·T(b) B. taurus, RR = -1,385 + 37·T(b) and crossbreds, RR = -2,226 + 59·T(b). Three SR equations (Maia, McArthur, and Gatenby models) from the literature were evaluated against the Thompson model using the 14 studies. The McArthur model predicted SR within the correct range, but with an increased slope bias because the equation was linear and not the correct shape. The Maia model overpredicted SR for all breed types with the greatest overprediction being for crossbreds. The Gatenby model overpredicted SR for B. taurus (root mean square error of prediction = 506 g·m(-2)·h(-1)), but was the best predictor for B. indicus. The Thompson model overpredicted SR for B. indicus (root mean square error of prediction ranged from 134 to 265 g·m(-2)·h(-1)), but was the best predictor for B. taurus and crossbreds. The Thompson model was a good predictor for RR across all breed types. The meta-analysis showed that the Thompson model outperformed previous models for both RR and SR with the exception of the SR of B. indicus, which was best predicted by the Gatenby model.
Associations between reproductive and carcass traits in Nellore
Publisher: Universidade Estadual de Londrina
Date: 16-12-2015
DOI: 10.5433/1679-0359.2015V36N6SUPL2P4423
Abstract: The objective of this study was to estimate the genetic parameters and (co)variance of Nellore animals and to characterize the associations between these characteristics for the following carcass traits: weight (W), longissimus muscle area (LMA), rump fat thickness (RF) and fat thickness between the 12th and 13th ribs obtained by ultrasound (BF) also, the following reproductive traits: age at first calving (AFC), first calving interval (FCI), scrotal circumference at 450 and 550 days of age (SC450 and SC550). The genetic parameters were estimated by a single-trait and two traits animal model using Bayesian inference. The model used for all of the features included the genetic random effect and age as covariate assuming a quadratic effect. Additionally, sex, month and year of birth and management of creation and environmental effects identified were included for the carcass traits. For AFC, FCI and SC450 and SC550, we considered only the month and year of birth. The heritability estimates for all of the traits were higher in the two traits analysis, except for AFC and FCI, which showed 0.75 and 0.29, respectively, similar values in the single trait analysis. The two traits analyses resulted in heritability estimates for a posteriori for the features W, LMA, BF, RF, SC450 and SC550 of 0.49, 0.66, 0.74, 0.68 0.66 and 0.74, respectively, suggesting the possibility of genetic gains during a short period of time. The genetic correlations between AFC and carcass traits measured by ultrasound were close to zero. A similar trend was found for AFC, SC450 and SC550 days, indicating that the selection for these traits does not promote changes in AFC. High genetic correlations (0.92, 0.93 and 0.94) were observed between the characteristics LMA and W, BF and RF, and SC450 and SC550, respectively.
Effects of supplementation and stocking rate on body condition and production parameters of multiparous beef cows
Publisher: Cambridge University Press (CUP)
Date: 12-2005
DOI: 10.1079/ASC50950403
Abstract: Fall-calving multiparous Angus × Hereford cows 3 to 10 years of age were stratified by age in a three by two factorial treatment arrangement to evaluate the efficacy of modifying stocking rate and supplementation strategy to manage cow body condition and production parameters over a 5-year study. Efficacy was evaluated quarterly in association with calving, breeding, weaning, and mid way between weaning and calving (i.e. in August). Three protein supplementation strategies (none, standard, strategic) were imposed across both a moderate (0·3 cows per ha) and a high (0·4 cows per ha) stocking rate. In the strategically supplemented group, protein supplement was provided to cows with a body condition score ·5 at the quarterly evaluations. There was an effect of supplementation on pregnancy rate, which in combination with previously established culling practices resulted in different age profiles amongst supplementation strategies in years 2 to 5 ( P 0·01). Two statistical analyses were therefore conducted to dissociate the confounding effects of supplementation strategy and age. One model included the effect of stocking rate, supplementation strategy, production year, and all interactions the second included the addition of age and its interactive effects. Stocking rate and supplementation strategy affected pregnancy rate in each of the models ( P = 0·003 and P = 0·10, respectively). Standard, non-supplemented and strategically supplemented animals had estimated pregnancy rates of 0·83, 0·76, and 0·79, respectively ( P = 0·10). The effects of nutrition on both calving interval and birth weight were independent of the model employed. Animals that were not supplemented had extended calving intervals ( P = 0·06), but there was no effect of stocking rate ( P 0·10). Birth weight was not affected by supplementation strategy or stocking rate ( P 0·10). The lower 205-day weights of calves on a heavy compared with moderate stocking rate was independent of age ( P = 0·02). However, the increased 205-day weight of calves born to strategically supplemented cows compared with those born to unsupplemented cows was only evident when data were not corrected for differences in age among groups ( P = 0·03). Likewise, analyses of cow condition parameters using models without and with age resulted in different interpretations. These results suggest that strategic and standard supplementation result in similar animal performance and that the improvement in herd productivity associated with altering stocking rate and supplementation may partially be due to altered herd age dynamics.
The effect of nutritional status on protein degradation and components of the calpain system in skeletal muscle of weaned wether lambs
Publisher: Cambridge University Press (CUP)
Date: 12-1997
DOI: 10.1017/S0021859697004784
Abstract: The association between the rate of protein degradation and the components of the calpain system in lambs fed at sub-maintenance, maintenance and supra-maintenance levels of nutrition was investigated. Weights of the cold carcass, liver, kidney, pluck and m. semitendinosus increased with nutritional level ( P ·05). The rate of protein degradation in the hind-limb was determined using an in vivo arterio-venous method. Blood flow, protein gain and protein synthesis across the hind-limb increased with nutritional status ( P ·05). There was an increase in the amount of protein synthesised per unit of RNA (mg RNA/g protein) with improved nutritional status. The rate of protein degradation across the hind-limb increased between the sub-maintenance and maintenance treatments ( P ·05) but there was no further increase above maintenance ( P ·10). The activity of the components of the calpain system was determined after separation on a DEAE-Sepharose column with a stepwise gradient with increasing NaCl concentrations. Although there were no significant effects of nutritional status on the components of the calpain system, there was a negative association between the rate of protein degradation and the activity of μ-calpain ( R 2 =0·61 P ·005) and a weak positive association between calpastatin activity and protein gain ( R 2 =0·44 P ·05).
Chemical composition and ruminal degradation kinetics of crude protein and amino acids, and intestinal digestibility of amino acids from tropical forages
Publisher: FapUNIFESP (SciELO)
Date: 03-2012
Performance, residual feed intake, digestibility, carcass traits, and profitability of angus-hereford steers housed in individual or group pens
Publisher: Oxford University Press (OUP)
Date: 2010
Abstract: Even though the concept of residual feed intake (RFI) is well accepted, several questions remain regarding other traits that may be associated with selection for decreased RFI. These include DM digestibility, carcass composition, profitability, and performance. The objective of this study was to investigate the difference in those traits between low- and high-RFI cattle. Sixty Angus x Hereford crossbred steers (296 kg of initial BW) were fed a corn-based finishing ration (1.68 Mcal of NE(m)/kg, 13% CP on a DM basis) during 2 periods of 60 d each. For both phases, the regression equation fitted without the intercept (not statistically significant) was DMI (kg/d) = 0.0701 x BW(0.75) + 2.714 x ADG, r(2) = 0.42. The 15 greatest and least RFI steers were classed as high and low RFI groups. There were no differences between low and high RFI groups for days on feed (162 vs. 168 d), slaughter weight (503 vs. 511 kg), HCW (317 vs. 315 kg), LM area (76.5 vs. 77.1 cm(2)), backfat (1.23 vs. 1.27 cm), KPH (3.1 vs. 3.7%), quality grade (average Choice for both groups), or carcass fat (32.4 vs. 33.1%). Visceral organ masses and abdominal fat were similar for low and high RFI groups (32.25 vs. 31.24 kg and 37.48 vs. 36.95 kg, respectively). These results do not support the existence of major differences in composition and organ mass between low and high RFI steers at slaughter. The RFI grouping had a significant effect on DMI, G:F, and RFI values. Stepwise regression showed that G:F alone or DMI and ADG together explained 98.5% of the variance in cost of BW gain, whereas RFI alone explained only 18%. We conclude that RFI is less useful than G:F as an indicator of feedlot efficiency and profitability.
Genotype-environment interaction of maternal influence characteristics in Nellore cattle bred in the Brazilian humid tropical regions by reaction norm
Publisher: Universidade Estadual de Londrina
Date: 17-08-2015
Modeling Feed Efficiency
Publisher: Wiley
Date: 10-07-2012
Effects of the β-agonist, cimaterol, on growth, body composition and energy expenditure in rats
Publisher: Cambridge University Press (CUP)
Date: 07-1988
DOI: 10.1079/BJN19880079
Abstract: 1. Male Sprague-Dawley rats weighing 146·5 ( se 4·3)g were fed on a semi-synthetic diet containing 0, 25 or 150 mg cimaterol/kg for 12 d. Net changes in weight and composition of carcass, liver, heart, gastrointestinal tract, gastrocnemius plus plantaris muscles, skin and remainder were estimated by comparative slaughter. 2. Cimaterol increased protein gains in gastrocnemius plus plantaris muscles from 0·09 g in controls to 0·14 and 0·12 g in 25 and 150 mg cimaterol/kg groups respectively. Carcass protein gains increased from 6·27 g in controls to 8·00 and 7·05 g in 25 and 150 mg cimaterol/kg groups respectively. 3. Rats treated with cimaterol either gained less fat or actually lost fat from all tissues studied, whilst control rats gained fat. These changes were reflected in lower energy retention in cimaterol-fed rats. 4. Energy intake was not affected by treatment. Cimaterol increased heat production from 776 kJ/kg body-weight 0·75 in controls to 863 kJ/kg body-weight 0·75 in both treated groups. Gross efficiency was reduced from 17·4% in controls to 8·0 and 7·7% in rats fed on 25 and 150 mg cimaterol/kg diets respectively. 5. These results indicate that cimaterol increases protein gain at the expense of fat in rats. In addition, subcutaneous adipose tissue appears to be more sensitive than abdominal fat, whilst protein gains are particularly enhanced in skeletal muscle relative to other body tissues.
Multivariate approach of inter-relationships among growth, consumption and carcass traits in Nellore cattle1
Publisher: FapUNIFESP (SciELO)
Date: 03-2014
β-adrenergic agonists and hypertrophy of skeletal muscles
Publisher: Elsevier BV
Date: 1992
DOI: 10.1016/0024-3205(92)90374-X
Abstract: Chronic administration of some beta-adrenergic agonists markedly stimulates hypertrophy of skeletal muscles. It appears that type II fibers are more responsive to beta-adrenergic agonists than type I fibers. The hypertrophic effect of beta-adrenergic agonists is transient, with the effect diminishing during prolonged treatment. Similarly, some cellular responses including the increase in RNA concentration and the decrease in calpain I activity are also short-lived. Recent evidence suggests that the temporal response is associated with decreased beta-adrenoceptor density. Both increased rate of protein synthesis and/or decreased protein degradation have been suggested as the mechanism of action of these compounds on hypertrophy of skeletal muscles. It is important to consider the temporal nature of cellular responses to chronic treatment of beta-adrenergic agonists as well as the differential effects of these compounds on protein metabolism among skeletal muscle fiber types when investigating the mechanism(s) of action of these compounds.
Genetic correlation of traits measured by ultrasound at yearling and 18 months of age in Nellore beef cattle
Publisher: Elsevier BV
Date: 10-2015
Growth performance, and carcass and meat quality traits in progeny of Poll Nellore, Angus and Brahman sires under tropical conditions
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/AN13505
Abstract: This study aimed to characterise progeny of sires representing major families in the Poll Nellore breed. Fourteen Poll Nellore sires, two Angus sires and one Brahman sire were mated by AI to ~400 multiparous Poll Nellore dams. Calves were raised and stocked on pasture in central Brazil until reaching ~18 months of age, then fed a sugarcane bagasse-based diet on an ad libitum basis until reaching market weight and finish (average 23 months). There were 236 Poll Nellore (N), 38 Angus × Poll Nellore (AN) and 31 Brahman × Poll Nellore (BN) calves born in total. The weaning and 423-day weight weights, and growth rates and pre- and post-weaning were greater (P 0.05) in males than in female calves, and were influenced by breed and by sire within the N animals. The weaning weights were higher (P 0.05) in AN and BN than in N calves. The 423-day weight weights were greater (P 0.05) in AN calves, followed by BN, with straightbred N being lightest. Feedlot average daily gain was unaffected (P 0.05) by sex or by sire within N, but was lowest (P 0.05) in N cattle, and highest in AN and BN animals, which did not differ (P 0.05). Heifers reached the end of the study with lower bodyweight (BW) and dressing percentage than steers, resulting in lower carcass weights, smaller longissimus muscle areas (LMA), but greater 12th to 13th rib backfat (BF) and similar marbling score and mean shear force. However, the proportion of carcasses grading Choice or Prime was numerically greater in heifers than in steers (23.6% vs 9.8%). AN cattle reached greater harvest weights than BN, and those were heavier than N cattle (P 0.001). However, dressing percentages were lowest in AN animals, so that there was no significant difference in carcass weight between AN and BN cattle. AN carcasses also had greater LMA, BF and marbling scores than the N carcasses. The proportion of carcasses grading Choice or Prime was numerically greater in AN cattle than in the BN and N groups (25.9%, 11.8% and 15.9%, respectively). Steaks from AN calves were more tender than N steaks, with the BN steaks being intermediate. There was significant variation among N sires for final BW, dressing percentage, carcass weight, LMA and marbling score, but not for BF or mean shear force. The percentages of carcasses of N cattle grading Choice or Prime ranged from 0% to 61.5%. Three N sires produced progeny with greater than 40% of carcasses grading Choice or above (Berílio OB, Furador OB, and Litoral OB). Likewise, three N sires (Blitz OB, Furador OB and Sossego OB) had progeny with 67%, 62% and 75%, respectively, of steaks classified as tender. This study confirmed that Zebu cattle have inferior carcass and meat quality relative to AN crossbreds under tropical conditions, however there is substantial variation within the N breed for these traits, and several sires have a proportion of their progeny comparable in terms of meat tenderness to those of Angus sires.
Development of a dynamic, mechanistic model of lamb metabolism and growth
Publisher: Cambridge University Press (CUP)
Date: 12-1990
DOI: 10.1017/S0003356100012575
Abstract: A dynamic, mechanistic model of lamb metabolism and growth was developed for the purpose of evaluating hypotheses regarding the mechanisms of action of growth promotants. The model relates tissue growth to DNA accretion and protein turn-over. State variables include circulating amino acids, glucose, lipids and acetate four protein pools (carcass, viscera, other tissues and wool) and storage triacylglycerol are also included. Equations are mainly of the Michaelis-Menten form, allowing for nutrient utilization patterns to be determined by relative tissue affinities for substrates (ko.5), enzymatic capacities (Vmax) and substrate concentrations ([S]). Protein degradation rates are defined as first-order with respect to protein. The model adequately simulated growth from 20 to 40 kg empty body weight. Simulated changes in nutrient input yielded reasonable energy balance response patterns, although theoretical growth efficiencies were greater than those observed in practice. Variations in volatile fatty acid absorption patterns were accommodated well, with predicted nitrogen retention closely approximating experimental observations. The model also responded appropriately to changes in dietary protein level, with body fat varying inversely with amino acid absorption. In summary, the model was found to perform adequately for the purpose of examining mechanisms responsible for alteration of growth and body composition.
Feedlot performance, feed efficiency reranking, carcass traits, body composition, energy requirements, meat quality and calpain system activity in Nellore steers with low and high residual feed intake
Publisher: Elsevier BV
Date: 12-2012
Estimation of (co)variances for growth traits in Nellore cattle raised in the Humid Tropics of Brazil by random regression
Publisher: Universidade Estadual de Londrina
Date: 10-06-2015
Protein metabolism, feed energy partitioning, behavior patterns and plasma cortisol in Nellore steers with high and low residual feed intake
Publisher: FapUNIFESP (SciELO)
Date: 2013
Correlações genéticas entre escores visuais e características de carcaça medidas por ultrassom em bovinos de corte
Publisher: FapUNIFESP (SciELO)
Date: 02-2009
DOI: 10.1590/S0100-204X2009000200012
Abstract: O objetivo deste trabalho foi estimar correlações genéticas e fenotípicas entre escores visuais e características de carcaça medidas por ultrassom, para verificar a eficácia desses escores na determinação da musculosidade e na avaliação da carcaça. As características de carcaça medidas por ultrassom foram área de olho de lombo (AOL) e espessura de gordura subcutânea (EG), mensuradas entre a região da 12ª e 13ª costelas, bem como a espessura de gordura subcutânea na garupa (EGP8). As características de estrutura (E), precocidade (P) e musculosidade (M) foram avaliadas por meio de escores visuais. Os componentes de covariância usados para estimar as correlações genéticas e fenotípicas foram obtidos pelo método da máxima verossimilhança restrita, em uma análise multicaracterística. As estimativas de correlações genéticas entre AOL e E, P e M foram 0,54, 0,58 e 0,61, respectivamente, e indicaram que, a longo prazo, a utilização da AOL como critério de seleção poderá produzir animais com maiores escores visuais para essas características. As correlações genéticas estimadas entre as espessuras de gordura (EG e EGP8) e os escores P e M apresentaram comportamento semelhante. Entretanto, as correlações genéticas entre as espessuras de gordura (EG e EGP8) e E foram próximas de zero. As correlações fenotípicas seguiram as mesmas tendências das respectivas correlações genéticas. Essas estimativas indicam que os escores visuais são determinados, em parte, pelos mesmos conjuntos de genes que influenciam a AOL.
Effects of dietary protein, fat and restriction on body composition and energy balance in lactating rats
Publisher: Elsevier BV
Date: 08-1986
Abstract: Isoenergetic diets formulated at three levels of dietary protein using 12,24 and 40% casein and at two levels of fat using 2.26 and 13.82% corn oil were fed at five levels of intake, ad libitum, 75, 62.5, 50 and 37.5% of average ad libitum intake, to 90 lactating rats from d 7 to 14 of lactation. Regression equations developed from lactating rats killed on d 7 of lactation were used to calculate initial body composition and energy of rats killed on d 14 of lactation. Changes in body weight and body water were significantly (P less than 0.05) affected by dietary fat and protein, but change in dry lean body mass was affected only by level of dietary fat, whereas body nitrogen and fat and lean body energy were not affected by level of dietary fat or protein. However, restricted intake significantly increased loss of all these. Likewise, restricted intake decreased milk production. Changes in weights of heart and liver were not affected by diet or intake, whereas intestinal weight decreased with intake restriction. Liver enzyme activities were markedly affected by intake restriction, whereas responses to dietary protein and fat were marginal.
Genetic structure of the tudanca bovine breed inferred from the genealogical information,Estructura genética de la raza tudanca inferida de información genealógica
Publisher: SciELO Espana/Repisalud
Date: 09-2011
Effect of genotype and nutrition on calpastatin inhibitory activity and mRNA abundance in milk-fed lambs
Publisher: Elsevier BV
Date: 1993
DOI: 10.1016/0300-9084(93)90050-3
Abstract: Muscle proteolysis is controlled by a wide range of enzyme systems. The reported effects of the calcium dependent proteinases (calpain I and II) and its specific inhibitor (calpastatin) on myofibrillar structure, has led to the speculation that this system may have a pivotal role in regulating protein turnover and muscle growth. The present study highlights the possibility of protein degradation being subject to genetic variation. The relationship between genotype, level of nutrition, muscle protein turnover and the calpain system in young milk-fed lambs was assessed. Male lambs which had been selected for 10 generations for high (W+) and low (W-) weight at weaning were used in the study. Lambs were removed from their mothers 4 days after birth and surgically fitted with abomasal catheters and infused with reconstituted milk replacer at a high or a low rate. At 8 weeks of age, measurements of muscle protein gain, synthesis and degradation were performed, the animals were slaughtered and s les rapidly removed for subsequent chemical analysis. The liveweight gain and weight of the m vastus lateralis was reflected (P < 0.001) in the designed differences in nutrient supply. The weight of the m vastus lateralis was greater (P < 0.01) in the W+ compared to the W- lambs. The rate of protein synthesis and calculated degradation were greater (P < 0.05) in W+ than W- lambs. Calpain I and II and calpastatin activity were not significantly altered by genotype or nutrition. Calpastatin mRNA abundance increased significantly (P < 0.05) between 1 and 8 weeks of age. Regression analysis revealed genotype-specific responses with respect to calpastatin activity and mRNA abundance.(ABSTRACT TRUNCATED AT 250 WORDS)
Effects of growth hormone-releasing factors and cottonseed meal on hormones and metabolites in plasma from lambs fed lucerne chaff ad libitum
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/AR9941125
Abstract: This study was part of an experiment on the effects of cottonseed meal (CSM) and growth hormone-releasing factor (GRF) on growth in lambs fed lucerne chaff. Forty-eight crossbred lambs were fed lucerne chaff ad libitum, alone or with a cottonseed meal supplement (CSM 300 g/day). Eight lambs from each group were injected twice daily with recombinant or synthetic GRF (rGRF and sGRF respectively 30 8g per kg body weight/day) or excipient only for 28 or 30 days. Jugular blood s les were obtained on days 0, 7, 14, 21 and 28. On day 29, blood s les were taken from selected lambs (n = 2/group) at 0, 20, 40, 60, 80, 100, 120, 160 and 240 min after injection. Supplementation of lucerne chaff with CSM generally increased glucose and urea concentrations in plasma, reflecting improved energy and protein status. However, concentrations of growth hormone, insulin-like growth factor-1 and insulin were unaffected by CSM, as were plasma proteins, triacylglycerols and non-esterified fatty acids. Injection of rGRF and sGRF stimulated secretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin. Peak GH concentrations (20 min) following injection of GRF appeared to be higher in lambs fed CSM than in those receiving lucerne chaff alone. In contrast, maximal concentrations of IGF-1 were seen after 14 days of treatment. These changes were accompanied by increased plasma glucose, with no changes in triacylglycerols, non-esterified fatty acids and protein. Plasma urea was reduced by GRF, indicating that amino acids were erted away from catabolism towards protein synthesis. These two sources of GRF were very similar in their endocrine and metabolic effects. This confirms similar observations regarding their effects on growth performance and carcass composition.
Selection Indices and Multivariate Analysis Show Similar Results in the Evaluation of Growth and Carcass Traits in Beef Cattle
Publisher: Public Library of Science (PLoS)
Date: 20-01-2016
Genetic and environmental factors affecting ultrasound measures of longissimus muscle area and backfat thickness in Nelore cattle
Publisher: Elsevier BV
Date: 09-2008
Effect of maternal administration of salbutamol to sows on post-natal growth and carcass characteristics in the progeny
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/AR9940271
Abstract: The effects of salbutamol administration to pregnant sows on post-natal growth and carcass characteristics of the progeny were investigated. Salbutamol (4 mg/kg diet) was fed to sows during the first (0 to 38 days, TI), second (39 to 78 days, T2) or third (79 days to term, T3) trimester of pregnancy. At birth, maternal administration of salbutamol had no effect on body weight, dressing percentage or weights of liver, heart, semimembranosus and semitendinosus muscle in proportion to body weight in the progeny. No significant effects of maternal treatment with salbutamol on body weight, dressing percentage, semitendinosus muscle weight in proportion to body weight and loin eye area were observed in the progeny at 21 days. P2 fat depth at 21 days was greater (P 0-05) in TI than in controls. The percentage of type I fibres in the deep portion of semitendinosus muscle was higher (P 0.05) in treatment groups as compared with controls: 27.4, 42.8, 36.9 and 36.0% in control, TI, T2 and T3 respectively. At slaughter (90 kg), carcass and meat parameters including length, P2 fat depth, meat colour and drip loss were not affected by maternal administration of salbutamol. However, loin eye areas were larger in T1 than in controls. Larger loin eye areas, coupled with numerically (but not statistically) significant heavier carcasses and lower backfats, resulted in greater estimates of carcass protein mass in TI pigs as compared with controls (P = 0.06).
The development of a dynamic, mechanistic, thermal balance model for Bos indicus and Bos taurus
Publisher: Cambridge University Press (CUP)
Date: 22-08-2014
DOI: 10.1017/S002185961300049X
Abstract: The dynamic model presented in the current paper estimates heat production and heat flow between growing and mature cattle ( Bos indicus and Bos taurus ) and the surrounding environment. Heat production was calculated using the NRC (2000) and heat flows between the animal and the environment were based largely on existing models and physical principles. Heat flows among the body core, the skin, the coat and the environment were calculated. Heat flows from and to the environment included solar radiation, long wave radiation, convection and evaporative heat loss. Physiological responses of cattle (sweating, panting and vasodilation) were modelled through mechanistic equations. The model required weather (radiation, temperature, wind and vapour pressure), animal (body-core weight and genotype-specific parameters) and dietary inputs (dry matter intake rates and diet composition) and estimated heat balance and the physiological responses of the animal to within-day weather variation. The current paper has focused on heat stress, although the model was designed to run under both hot and cold climatic conditions. The model developed in the current paper provides researchers and livestock producers with the ability to predict heat stress and to evaluate mitigating procedures.
Cimaterol reduces beta-adrenergic receptor density in rat skeletal muscles.
Publisher: Oxford University Press (OUP)
Date: 1992
DOI: 10.2527/1992.701115X
Abstract: Interactions between the beta-adrenoceptor agonist cimaterol and beta-adrenoceptors on rat skeletal muscle membranes were examined in two studies. In Exp. 1, muscle s les from eight Sprague-Dawley rats (female, approximately 200 g) were used for competition binding and autoradiographic studies using [125I]cyanopindolol (ICYP) as a radioligand. The affinities or dissociation constants for binding (KD values) for cimaterol in plantaris and soleus muscles were .68 and .92 microM, respectively. Muscle areas stained for succinic dehydrogenase had propranolol-resistant ICYP binding sites cimaterol did not seem to compete for these sites. In Exp. 2, 60 Sprague-Dawley rats (female, approximately 218 g) were fed 0 or 10 ppm of cimaterol in rat diet that was ground. Groups were killed after 1, 3, 7, 14, or 28 d of treatment. Cimaterol increased BW gain up to 14 d after commencement of treatment, with little or no improvement thereafter. Enhanced weight gain in skeletal muscles also occurred up to 14 d of cimaterol treatment. Densities of beta-adrenoceptors in plantaris and soleus muscle membrane homogenates were estimated using a radioligand binding assay with ICYP. A significant reduction in the number of binding sites (Bmax) was observed after 3 d of cimaterol treatment in plantaris muscle without a change in the KD of ICYP binding. The percentage reductions in Bmax were 26.8, 42.2, 37.7, and 37.8% at 3, 7, 14, and 28 d after cimaterol administration, respectively. In the soleus muscle, significant reductions (44.1 and 29.8%) in Bmax were observed after 3 and 14 d of cimaterol treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Mathematical models in ruminant nutrition,Modelos matemáticos na nutrição de ruminantes
Publisher: FapUNIFESP (SciELO)
Date: 2005
DOI: 10.1590/S0103-90162005000100015
Abstract: Mathematical models can be used to improve performance, reduce cost of production, and reduce nutrient excretion by accounting for more of the variation in predicting requirements and feed utilization in each unique production situation. Mathematical models can be classified into five or more categories based on their nature and behavior. Determining the appropriate level of aggregation of equations is a major problem in formulating models. The most critical step is to describe the purpose of the model and then to determine the appropriate mix of empirical and mechanistic representations of physiological functions, given development and evaluation dataset availability, inputs typically available and the benefits versus the risks of use associated with increased sensitivity. We discussed five major feeding systems used around the world. They share common concepts of energy and nutrient requirement and supply by feeds, but differ in structure and application of the concepts. Animal models are used for a variety of purposes, including the simple description of observations, prediction of responses to management, and explanation of biological mechanisms. Depending upon the objectives, a number of different approaches may be used, including classical algebraic equations, predictive empirical relationships, and dynamic, mechanistic models. The latter offer the best opportunity to make full use of the growing body of knowledge regarding animal biology. Continuing development of these types of models and computer technology and software for their implementation holds great promise for improvements in the effectiveness with which fundamental knowledge of animal function can be applied to improve animal agriculture and reduce its impact on the environment.
Glycemic responses in white sturgeon after oral administration of graded doses of D-glucose
Publisher: Elsevier BV
Date: 06-2003
Relationship between body condition score and production of multiparous beef cows
Publisher: Elsevier BV
Date: 10-2006
Estimating feed efficiency: Evaluation of mathematical models to predict individual intakes of steers fed in group pens
Publisher: Oxford University Press (OUP)
Date: 05-2011
Abstract: To evaluate feed efficiency using residual feed intake (RFI), it is necessary to measure and record daily feed intake for each animal. This can be accomplished by housing them in in idual pens or by using sophisticated electronic feeders in group pens. All the available options are very expensive and very laborious therefore, several researchers have developed methods to predict in idual DMI of cattle fed in group pens. Three intake models were tested with a data set of 60 Angus × Hereford steers fed a corn-based finishing diet in both group and in idual pens. After the first 60 d (period 1) of the study, animals were switched from group to in idual pens, and then vice versa for another 60 d (period 2) thus, the entire feeding trial was 120 d long. No difference was observed in DMI between periods for steers fed in idually (period 1 = 10.9 kg/d and period 2 = 11.2 kg/d, P = 0.44), but a difference was observed in group pens (period 1 = 12.7 kg/d and period 2 = 10.9 kg/d, P < 0.01). In addition, no difference (P ≥ 0.15) was observed in carcass characteristics, such as HCW, dressing percentage, quality grade, LM area, KPH percentage, yield grade, or backfat between RFI groups (low, medium, and high). Average daily gain and G:F were not different between RFI groups within each period (P ≥ 0.06), but there were period differences (P < 0.001). Models 1 and 2 were based on growth, carcass composition, and nutrient requirements, whereas model 3 was based on the heterogeneity of pen intakes when cattle were rotated through the pens on a daily basis. Models 1 and 2 were forced through the mean observed DMI, so the mean bias was zero, but they were not precise, with a slope bias greater than 50%. Model 3 showed low accuracy (mean bias = 20%), but it was precise, with a slope bias of 21%. Because RFI is the error of the DMI equation, any inaccuracy when estimating intake will lead to a bias in the prediction of RFI. In conclusion, these models could be used to predict mean DMI, but they were not adequate for estimating RFI.
Evaluation of hypotheses regarding mechanisms of action of growth promotants and repartitioning agents using a simulation model of lamb metabolism and growth
Publisher: Cambridge University Press (CUP)
Date: 12-1990
DOI: 10.1017/S0003356100012587
Abstract: Responses of lambs to cimaterol (CIM), diethylstylbestrol (DES) and ovine growth hormone (GH) were examined using a mechanistic model of growing lamb metabolism. All three compounds increase growth of lean tissue (protein) and decrease fat gain, although the magnitudes of these responses vary. Our working hypothesis was that observed changes in nutrient partition between lean and fat gain were caused by alteration of rate constants for turn-over of muscle protein and fat. In idual experiments were simulated whilst varying values of the protein degradation constant (Kprolein) and Vmax for lipolysis (Kfat). Optimal parameter values were found by minimizing residual errors, calculated as the deviations of model predictions from experimental values for carcass protein and fat. Fitted values of Kfat and Kprotein (expressed as proportions of controls) for each simulation were: CIM (grazing), 1·20 (s.d. 0·05) and 0·86 (s.d. 0·025) CIM (pellet-fed), 1·11 (s.d. 0·115) and 0·87 (s.d. 0·032) DES, 1·33 (s.d. 0·111) and 0·94 (s.d. 0·024) GH, 1·77 (s.d. 0·139) and 0·97 (s.d. 0·025) respectively. These results demonstrate that different mechanisms may be responsible for the changes in carcass composition due to 3-adrenergic agonists, anabolic steroids and growth hormone. CIM probably exerts its effects via changes in protein and fat metabolism, whereas DES and GH appear to act mainly through changes in adipose tissue, with little or no effect on the rate constant for protein turn-over. Carcass composition is less sensitive to manipulation of adipose tissue metabolism than to changes in muscle protein metabolism.
The evaluation of a dynamic, mechanistic, thermal balance model for Bos indicus and Bos taurus
Publisher: Cambridge University Press (CUP)
Date: 28-08-2014
DOI: 10.1017/S0021859613000506
Abstract: The Thompson model (Thompson et al. , in press ), a heat balance model for cattle, was evaluated for Bos indicus and B. taurus under different climate conditions through the use of two local and one global sensitivity analyses and tested against independent datasets. The local analyses, which evaluate the in idual effects of parameters on model output, showed that the vasodilation/vasoconstriction parameter and reference body temperature ( T bref ) strongly affected body temperature. The global analysis, which evaluates the overall effect of parameters on model output, showed that 6 out of 24 parameters account for 0·79–0·89 of the model variation. The high proportion of variation accounted for by the parameters demonstrates that the model is linear in its parameters, with little interaction between the parameters. The Thompson model was tested against four independent datasets which included both B. indicus and B. taurus animals. The prediction of the relationship between skin and body temperature from the model aligned closely with the relationship in the datasets ( R 2 ranged from 0·55 to 0·87, mean bias ranged from 0·32 to 1·49). The prediction of sweating and respiration rates from the model aligned closely with the rates measured in the datasets ( R 2 ranged from 0·80 to 0·98 and 0·79 to 0·93, respectively). The delay in the diurnal body temperature variation, relative to air temperature, was more accurately predicted for cattle in the sun than for cattle in climate chambers. Given the limited datasets for construction and parameterization (both of which are described in Thompson et al., in press ), the model evaluated in the current study performed relatively well compared to the literature and known biology.
Energy partitioning and modeling in animal nutrition
Publisher: Annual Reviews
Date: 07-1995
DOI: 10.1146/ANNUREV.NU.15.070195.001203
Abstract: We first present a brief discussion of early and current models (feeding systems) used to estimate animal energy and protein requirements and to predict performance based on feed composition and intake. We then touch on some limitations inherent in these systems. Next, we propose that dynamic (i.e. time-variant) models and mechanistic models (i.e. equations based on knowledge of physiological functions) are superior to earlier systems for both practical and research applications. Finally, we describe a number of applied and research models of animal growth and lactation to illustrate how biological concepts may be represented in equation form. Equations that represent current knowledge of underlying functions can be used to improve predictions of animal requirements and performance and to evaluate hypotheses about nutritional and physiological mechanisms that influence animal performance.
Performance and health of Holstein calves fed different levels of milk fortified with symbiotic complex containing pre- and probiotics
Publisher: Springer Science and Business Media LLC
Date: 24-08-2016
DOI: 10.1007/S11250-016-1127-1
Abstract: The objective of this study was to evaluate the performance and health of Holstein calves fed low or high milk supply (MSP) with or without symbiotic complex (SYM) supplementation, consisting of prebiotics, probiotics, and fibrolytic enzymes. Thirty-two Holstein calves with body weight (BW) of 34 ± 7 kg were distributed in a randomized block design in a 2 × 2 factorial arrangement. Treatments consisted of low and high MSP: 10 % of BW from 1st to 8th weeks after birth (low) and 20 % BW from 1st and 2nd weeks after birth, 15 % BW for the 3rd and 4th weeks after birth, and 10 % BW from 5th and 8th weeks after birth (high). Solid ration was supplied in addition to milk. Intake, ADG, diet digestibility, and fecal consistency index were evaluated. Low and high MSP groups tended (P < 0.10) to differ in calf growth, final BW (69 vs. 73 kg), post-weaning average weight gain (548 vs. 788 g/day), and final average weight gain (549 vs. 646 g/day) in low and high MSP calves, respectively. There was an interaction between MSP level and SYM on the digestibilities of dry matter (DM) and neutral detergent fiber (NDF) (P < 0.10). In the low MSP group, inclusion of SYM increased digestibility of DM (0.720 to 0.736 g/kg) and NDF (0.758 to 0.783 g/kg). The inclusion of SYM improved calf health (P < 0.10) with a fecal score of 0.31 compared to 0.42 without SYM. Milk-feeding level was an important factor in calf performance, while SYM supplementation improved diet digestibility and animal health.
Relationships among dietary protein, feed intake and changes in body and tissue composition of lactating rats
Publisher: Elsevier BV
Date: 08-1986
Abstract: To quantify effects of protein and energy intake on changes in tissue composition in lactating rats, 36 rats were fed three diets (L, M and H, containing 12,24, and 36% protein, respectively) at four levels of intake (100, 70, 50 and 30% of ad libitum) from d 7 to 14 of lactation. Three rats per treatment were killed on d 14 carcass, viscera, liver and mammary glands were dissected and analyzed for water, fat, protein and ash. Twelve rats killed on d 7 provided initial composition estimates. All rats lost weight loss was affected slightly by diet but drastically by intake, ranging from 22.4 g in ad libitum-fed rats to 79.9 g in the 30% group. Fat losses, mostly from carcass, were insensitive to diet but were increased to maximum at the 70% intake level, and further restriction did not result in significantly greater fat losses. Protein losses in all tissues increased with degree of feed restriction. Protein losses in viscera, liver and mammary decreased with higher dietary protein. Possible homeorrhetic adaptations responsible for these patterns of nutrient partition are discussed in terms of changes in rates of fat and protein turnover and hormonal effects upon these rates.
Comparative analysis of two dynamic mechanistic models of beef cattle growth
Publisher: Elsevier BV
Date: 05-2008
Genetic association between body composition measured by ultrasound and visual scores in Brazilian Nelore cattle1
Publisher: Oxford University Press (OUP)
Date: 12-2012
Abstract: The objective of this study was to evaluate the genetic variability of body composition traits measured by ultrasound, growth traits, and visual scores as well as their genetic associations in Nelore cattle. A total of 9,765, 13,285, 13,061, 12,811, 3,484, 3,484, 3,483, and 3,303 records of weight at time of ultrasound measure (W550), 12th-13th rib LM area (LMA), backfat thickness (BF), rump fat thickness (RF), visual scores for body structure (BS), finishing precocity (FP), muscling (MS), and sheath and navel characteristics (SN), respectively, were used. The model included contemporary group (defined as year and season of birth, sex, and management group) as a fixed effect and age of dam at calving and age of the animal (linear and quadratic effects) as covariates. The direct additive genetic effect was included as a random effect. The analyses also included 46,157 observations of BW adjusted to 120 d. The (co)variance components were estimated by the restricted maximum likelihood method using a multitrait animal model. Heritability estimates for W550, LMA, BF, RF, BS, FP, MS, and SN were 0.37 ± 0.030, 0.33 ± 0.03, 0.24 ± 0.02, 0.28 ± 0.03, 0.24 ± 0.04, 0.38 ± 0.05, 0.29 ± 0.05, and 0.38 ± 0.06, respectively. The estimated genetic correlations between visual scores and LMA were moderate and positive, ranging from 0.37 to 0.44. Similar results were obtained for the estimated genetic correlations between FP and MS with fat thickness measures (BF and RF). Low genetic correlations were estimated between SN and BS and between SN and the body composition traits, indicating that selection for body composition traits and BS will not affect sheath and navel size. The estimated genetic correlations between weight adjusted to 120 d of age (W120) and W550 and BS were high (0.87 and 0.91) and moderate with LMA (0.49 and 0.55), FP (0.37 and 0.41), and MS (0.47 and 0.55). The visual scores and ultrasound-measured body composition traits have enough genetic variation for selection purposes in Nelore cattle. Selection based on visual scores for body structure, finishing precocity and muscling should lead to desired changes in body composition albeit much more slowly than direct selection on those traits measured by ultrasound. Selection for heavier BW at early ages should lead to favorable changes in yearling LM area and visual scores.
Enhanced skeletal growth of sheep heterozygous for an inactivated fibroblast growth factor receptor 3
Publisher: Oxford University Press (OUP)
Date: 11-2006
DOI: 10.2527/JAS.2006-255
Abstract: Normal fibroblast growth factor receptor 3 (FGFR3) acts as a negative bone growth regulator by restricting chondrocyte proliferation and endochondral bone elongation. In sheep, a heritable mutation that inactivates FGFR3 produces skeletal overgrowth when homozygous, this condition is commonly referred to as spider lamb syndrome (SLS). We hypothesized that sheep heterozygous for the inactivated FGFR3 mutation (FGFR3(SLS/+)) would exhibit enhanced long bone growth and greater frame size additionally, the isolated effects of increased bone growth would translate into greater BW and larger LM area relative to normal lambs at harvest. The current study investigated bone length and LM area of FGFR3(SLS/+) sheep at maturity and during growth. At maturity, FGFR3(SLS/+) ewes exhibited a larger frame size and longer bones than normal FGFR3(+/+) ewes (P < 0.05). Similarly, FGFR3(SLS/+) lambs had greater frame sizes than normal FGFR3(+/+) lambs, as indicated by increased metacarpal III length and height at withers (P < 0.05). The FGFR3(SLS/+) lambs took longer than the normal FGFR3(+/+) lambs to reach the 60-kg common BW harvest end point (P 0.2). A similar LM area produced in the context of a greater frame size and skeletal length produces a greater muscle volume, thereby potentially increasing meat yield. The results of this study suggest that FGFR3(SLS/+) animals exhibit a relaxation of the normal inhibition of chondrocyte proliferation, resulting in an increase in the overall frame size. The sheep industry could utilize the naturally occurring genetic mutation in FGFR3 to potentially increase meat yields with enhanced skeletal growth as an alternative to exogenous growth promotants.
Growth, carcass quality, and protein and energy metabolism in beef cattle with different growth potentials and residual feed intakes
Publisher: Oxford University Press (OUP)
Date: 04-2007
DOI: 10.2527/JAS.2006-373
Abstract: Twenty-four beef steers (predominantly Angus x Hereford, 14 to 18 mo of age, 403 +/- 3 kg of BW), were housed and fed in in idual pens for about 122 d. Twelve steers came from a herd that had been selected for growth (high growth HG) and the other 12 from a herd with no selection program (low growth LG). Another 6 steers (3 from each group) were slaughtered at the beginning to obtain the initial composition. All steers were fed the same corn-based diet (3.06 Mcal of ME/kg of DM, 13.6% CP) on an ad libitum basis. Two weeks before slaughter, total urine was collected for 5 d for estimation of 3-methylhistidine excretion and myofibrillar protein breakdown rates. Compared with LG steers, HG steers had less initial BW but greater final BW, DMI (7.52 vs. 6.37 kg/d), ADG (1.33 vs. 0.853 kg/d), G:F (0.176 vs. 0.133 kg/kg), ME intake (0.233 vs. 0.201 Mcal x kg of BW(0.75) x d(-1)), and retained energy (RE 0.0711 vs. 0.0558 Mcal x kg of BW(0.75) x d(-1)) gained more fat (676 vs. 475 g/d) and tended to gain more whole body protein (100 vs. 72 g/d), with no difference in residual feed intake (RFI). Estimated net energetic efficiency of gain (k(g)) and ME for maintenance (ME(m)) did not differ between the 2 groups, averaging 0.62 and 0.114, respectively. The HG steers had greater HCW (350 vs. 329 kg), backfat (16.1 vs. 11.6 mm), and yield grades (3.53 vs. 2.80), with a similar dressing percent, KPH fat, LM area, and marbling score. Skeletal muscle protein gain (70.2 vs. 57.6 g/d) and fractional protein accretion rate (0.242 vs. 0.197%/d) tended to be greater in HG than in LG steers. Steers were classified into low (-0.367 kg/d) and high (0.380 kg/d) RFI classes. Compared with the high RFI steers, low RFI steers consumed less DM (6.61 vs. 7.52 kg/d) and ME (0.206 vs. 0.234 Mcal x kg of BW(0.75) x d(-1)) and tended to gain less fat (494 vs. 719 g/d), but were similar for initial and final BW, ADG, G:F, protein gain, HCW, dressing percent, backfat, KPH fat, LM area, marbling score, and yield grade, as well as for all observations related to myofibrillar protein metabolism. Residual feed intake may be positively [corrected] correlated with ME for maintenance. The maintenance energy requirement increased by 0.0166 Mcal x kg(-0.75) x d(-1) for each percentage increase in fractional protein degradation rate, confirming the importance of this process in the energy economy of the animal.
Meta-analysis of factors affecting carcass characteristics of feedlot steers
Publisher: Oxford University Press (OUP)
Date: 11-2006
DOI: 10.2527/JAS.2006-175
Abstract: A meta-analysis was conducted to assess the effects of biological type (early-moderate or late maturity) and implant status (estrogenic, combination, or nonimplanted repeats included) on HCW (kg) LM area (cm2) 12th-rib fat thickness (fat thickness, cm) KPH (%), and intramuscular fat (%) at harvest, to provide inputs to an ongoing program for modeling beef cattle growth and carcass quality. Forty-three publications from 1982 to 2004 with consistent intramuscular fat data were evaluated. Two studies were undertaken: 1) with fat thickness as a covariate and 2) with BW as a covariate. The intercept-slope covariance estimate was not statistically different from 0 for LM area (P = 0.11), KPH (P = 0.19), and intramuscular fat (P = 0.74) in study 1, and for LM area (P = 0.44), fat thickness (P = 0.11), KPH (P = 0.19), and intramuscular fat (P = 0.74) in study 2 therefore, a reduced model without a covariance component was fitted for these carcass characteristics. A covariance component was fitted for HCW (P = 0.01, study 1 and P = 0.05, study 2) and for intramuscular fat (P = 0.05, study 2). In study 1, the results for maturity indicated differences between early-moderate and late maturity for HCW (P < 0.01) and LM area (P < 0.01) but no differences for KPH (P = 0.26) and intramuscular fat (P = 0.50) for implant status, an estrogenic or combination implant increased HCW by 2.9% (P = 0.27) or 4.8% (P < 0.01), increased LM area by 3.2% (P = 0.23) or 6.3% (P < 0.01), decreased intramuscular fat by 8.1% (P < 0.01) or 5.4% (P < 0.01), respectively, and decreased KPH by 7.6% (P = 0.34) for estrogenic implants but increased KPH by 1.1% (P = 0.36) for combination implants, compared with nonimplanted steers. In study 2, the results at 600 kg of BW for implant status (implant or nonimplant) indicated no differences for HCW (P = 0.63) and LM area (P = 0.73), but there were differences for fat thickness (P < 0.01), KPH (P < 0.01), and intramuscular fat (P < 0.01) the results for maturity (early-moderate or late maturity) indicated no differences for HCW (P = 0.94), but there were differences for LM area (P < 0.01), fat thickness (P < 0.01), KPH (P < 0.01), and intramuscular fat (P < 0.01). The difference between early-moderate and late maturity (studies 1 and 2) confirmed that frame size accounts for a substantial portion of the variation in carcass composition. Studies 1 and 2 also indicate that implant status had significant effects on carcass quality.
Compensatory growth and carcass quality in growth-restricted and refed beef steers.
Publisher: Oxford University Press (OUP)
Date: 1995
Abstract: Beef steers were fed in two phases 1) to determine the relative importance of changes in DMI, gastrointestinal tract fill, energy expenditures, and composition of gain in the compensatory growth phenomenon, 2) to compare the effects of growth restriction due to ad libitum consumption of a low-energy (low-concentrate) diet to those of limited intake of a high-energy (high-concentrate) feed, and 3) to examine changes in carcass composition and quality resulting from different types of growth restriction. During the growing phase (237 to 327 kg), steers were fed either a high- (C) of low- (F) concentrate diet. Diet F was available for ad libitum consumption (FA) and diet C was available either for ad libitum consumption (CA) or on a limited basis (CL) to match the live weight gains by the FA group. During the finishing phase (327 to 481 kg), all steers received diet C, either for ad libitum consumption (CA) or restricted (CL) to 70% of the intake by the corresponding CA steers. Backfat thickness was markedly reduced (P < .001) by final feed restriction (7.4 and 6.9 mm for CL-CL and FA-CL respectively), compared with CA-CA (12.6 mm). Backfat also was lower in CL-CA (11.6 mm, P < .10) and FA-CA (9.9 mm, P < .05) than in CA-CA steers. Conversely, marbling scores were similar among groups, except for the FA-CL steers, which had lower marbling scores than FA-CA and CL-CA steers (P < .05). Higher DMI following growth restriction were accompanied by increased rates of live weight (+54 and +27%) and empty body weight (EBW +57 and +43%) gain for CL-CA and FA-CA steers, respectively, compared with CA-CA steers. Gain:feed (EBW basis) were improved in some restricted/refed groups (+30, +13, and +10%, for Cl-CA, CL-CM respectively CA-CA. Increased DMI played a major role in the compensatory gain response in both CL-CA and FA-CA groups. Maintenance requirement was reduced (-17%) in CL-CA and increased in the FA-CA group (+21%) both changes affected the magnitude of compensatory gain in those animals. In contrast, composition of gain had little or no effect on the compensatory gain response. Programmed feeding can be used to manipulate carcass quality, but low-concentrate feeding during the growing phase may impair overall feedlot performance.
Exogenous growth hormone releasing factors and cottonseed meal improve growth performance and composition of gain in lambs fed lucerne chaff ad libitum
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/AR9941111
Abstract: Forty-eight crossbred wether lambs (38 kg) were randomly assigned to two dietary groups (LUC, chaffed lucerne ad libitum CSM, LUC plus 300 g cottonseed meal/lday) and two hormone treatment groups (rGRF, recombinant growth hormone-releasing factor (GRF) sGRF, synthetic GRF) plus controls (CON, excipient only), and slaughtered after treatment for 28 (n = 36) or 30 (n = 12) days. An initial slaughter group (n = 12) was killed on day 0. CSM reduced intake of lucerne chaff, but increased total feed intake. CSM also increased liveweight gain and wool growth, with no effect on feed conversion efficiency. CSM increased carcass weight and decreased subcutaneous fat depth, with no effect on dressing percentage or longissimus dorsi (LD) area. Meat tenderness tended to decrease with CSM supplementation. CSM increased carcass protein accretion ( P 0.01), with no significant change in fat gain or final composition (P 0.05). CSM increased weights of the pelt, liver and empty body, and decreased the proportion of digesta in liveweight. Weights of blood, forestomachs and small intestine tended to increase as well (P 0.10). Both sources of GRF had similar effects. Intakes were not significantly affected by GRF, but feed conversion efficiency improved (P 0.01) with GRF treatment (6.4 v. 9.2 feed:gain for GRF and CON respectively). Liveweight gains and final weights of the whole body and carcass were increased additively by CSM and GRF. GRF reduced fat depth and increased LD area, with no effect on dressing percentage, carcass length or meat tenderness. These changes reflected increased carcass protein and reduced fat contents, brought about by increased accretion of protein and water and reduced fat gain due to GRF. GRF increased weights of blood and liver beyond the general increase in body size. Cottonseed meal and GRF additively produced significant improvements in growth performance and carcass quality of young wether lambs fed a roughage diet. GRF may be a useful tool to improve livestock production under extensive and intensive conditions.
Visceral Organ Mass and Cellularity in Growth-Restricted and Refed Beef Steers
Publisher: Oxford University Press (OUP)
Date: 1997
Abstract: Beef steers were fed in two phases to compare the effects of diet and intake on growth and cellularity of visceral organs. During the growing phase (237 to 327 kg), steers were fed either a high (C) or low (F) concentrate diet. Diet F was available ad libitum (FA), whereas diet C was available either ad libitum (CA) or on a limited basis (CL) to match live weight gains of the FA group. During the finishing phase (327 to 481 kg), all steers received diet C either ad libitum (CA-CA, CL-CA, and FA-CA) or restricted (CL-CL and FA-CL) to 70% of the intakes of corresponding CA steers. Marked nutritional effects on liver growth (e.g., -25 and -15% in CL and FA, respectively, relative to CA) were due mainly to changes in cell size (i.e., protein:DNA), with smaller changes in cell numbers (i.e., DNA). Hyperplasia and hypertrophy played a role in growth of the forestomachs, although cell numbers and sizes tended to change in opposite directions, limiting magnitudes of changes in organ mass. Protein synthetic capacity (i.e., RNA) varied as well, often in parallel with cell number. This result differed from that observed in intestines, which maintained constant cell sizes but underwent marked changes in cell number. For liver, amounts of absorbed nutrients seemed to be the main factor driving hypertrophy. The organs of the gastrointestinal tract responded to physical and chemical signals, as shown by the effects of dietary fiber on growth of the forestomachs and intestines. Forestomachs responded mainly to diet fiber content, whereas the intestines responded to diet type and nutrient supply. Feeding programs for beef animals often include changes in diet type and periods of feed limitation, and these in turn affect visceral organ growth and metabolism. Because visceral organs are a major contributor to whole-body energy expenditures, factors affecting these tissues must be understood. This study supports the concept that workload determines organ size, but dietary factors influencing workload clearly vary for each organ.
Genetic associations between carcass traits measured by real-time ultrasound and scrotal circumference and growth traits in Nelore cattle1
Publisher: Oxford University Press (OUP)
Date: 2010
Abstract: The aim of the present study was to evaluate the genetic correlations among real-time ultrasound carcass, BW, and scrotal circumference (SC) traits in Nelore cattle. Carcass traits, measured by real-time ultrasound of the live animal, were recorded from 2002 to 2004 on 10 farms across 6 Brazilian states on 2,590 males and females ranging in age from 450 to 599 d. Ultrasound records of LM area (LMA) and backfat thickness (BF) were obtained from cross-sectional images between the 12th and 13th ribs, and rump fat thickness (RF) was measured between the hook and pin bones over the junction between gluteus medius and biceps femoris muscles. Also, BW (n = 22,778) and SC (n = 5,695) were recorded on animals born between 1998 and 2003. The BW traits were 120, 210, 365, 450, and 550-d standardized BW (W120, W210, W365, W450, and W550), plus BW (WS) and hip height (HH) on the ultrasound scanning date. The SC traits were 365-, 450-, and 550-d standardized SC (SC365, SC450, and SC550). For the BW and SC traits, the database used was from the Nelore Breeding Program-Nelore Brazil. The genetic parameters were estimated with multivariate animal models and REML. Estimated genetic correlations between LMA and other traits were 0.06 (BF), -0.04 (RF), 0.05 (HH), 0.58 (WS), 0.53 (W120), 0.62 (W210), 0.67 (W365), 0.64 (W450 and W550), 0.28 (SC365), 0.24 (SC450), and 0.00 (SC550). Estimated genetic correlations between BF and with other traits were 0.74 (RF), -0.32 (HH), 0.19 (WS), -0.03 (W120), -0.10 (W210), 0.04 (W365), 0.01 (W450), 0.06 (W550), 0.17 (SC365 and SC450), and -0.19 (SC550). Estimated genetic correlations between RF and other traits were -0.41 (HH), -0.09 (WS), -0.13 (W120), -0.09 (W210), -0.01 (W365), 0.02 (W450), 0.03 (W550), 0.05 (SC365), 0.11 (SC450), and -0.18 (SC550). These estimates indicate that selection for carcass traits measured by real-time ultrasound should not cause antagonism in the genetic improvement of SC and BW traits. Also, selection to increase HH might decrease subcutaneous fat as correlated response. Therefore, to obtain animals suited to specific tropical production systems, carcass, BW, and SC traits should be considered in selection programs.
BOARD-INVITED REVIEW: The biology and regulation of preadipocytes and adipocytes in meat animals1,2
Publisher: Oxford University Press (OUP)
Date: 04-2009
Abstract: The quality and value of the carcass in domestic meat animals are reflected in its protein and fat content. Preadipocytes and adipocytes are important in establishing the overall fatness of a carcass, as well as being the main contributors to the marbling component needed for consumer preference of meat products. Although some fat accumulation is essential, any excess fat that is deposited into adipose depots other than the marbling fraction is energetically unfavorable and reduces efficiency of production. Hence, this review is focused on current knowledge about the biology and regulation of the important cells of adipose tissue: preadipocytes and adipocytes.
Morphology and morphometry of in vivo- and in vitro-produced bovine concepti from early pregnancy to term and association with high birth weights
Publisher: Elsevier BV
Date: 09-2002
DOI: 10.1016/S0093-691X(02)00935-4
Abstract: This study was designed to characterize conceptus development based on pre- and postnatal measurements of in vivo- and in vitro-derived bovine pregnancies. In vivo-produced embryos were obtained after superovulation, whereas in vitro-produced embryos were derived from established procedures for bovine IVM, IVF and IVC. Blastocysts were transferred to recipients to obtain pregnancies of single (in vivo/singleton or in vitro/singleton groups) or twin fetuses (in vitro/twins group). Ultrasonographic examinations were performed weekly, from Day 30 of gestation through term. Videotaped images were digitized, and still-frames were used for the measurement of conceptus traits. Calves and fetal membranes (FM) were examined and measured upon delivery. In vitro-produced fetuses were smaller than in vivo controls (P < 0.05) during early pregnancy (Day 37 to Day 58), but in vitro/singletons presented significantly higher weights at birth than in vivo/control and in vitro/twin calves (P < 0.05). From late first trimester of pregnancy (Day 72 to Day 93), placentomes surrounding in vitro-derived singleton fetuses were longer and thinner than controls (P < 0.05). At term, the presence of giant cotyledons in the fetal membranes in the in vitro group was associated with a larger cotyledonary surface area in the fetal horn (P < 0.05). The biphasic growth pattern seen in in vitro-produced pregnancies was characterized by conceptus growth retardation during early pregnancy, followed by changes in the development of the placental tissue. Resulting high birth weights may be a consequence of aberrant placental development due to the disruption of the placental restraint on fetal growth toward the end of pregnancy.
Effects of age on body condition and production parameters of multiparous beef cows
Publisher: Oxford University Press (OUP)
Date: 07-2006
DOI: 10.2527/JAS.2005-733
Abstract: Pregnancy rate, calving interval, birth weight, weaning weight, and quarterly BCS were collected for 5 consecutive years on 454 fall-calving multiparous British crossbred cattle (3 to 10 yr of age) to evaluate associations of age with BCS and production parameters. Body weight and BCS were collected pre-calving, prebreeding, at weaning, and midway through the second trimester of pregnancy (August). Body condition score was correlated with age during all seasons (P < 0.01). At calving, breeding, and in August, 3-yr-old cows had the lowest BW and BCS, whereas 8-yr-old cows had the greatest. At weaning, these values were maximal in 10-yr-old cows. Pregnancy rate was near 80% up to 9 yr of age but decreased to 57% in 10-yr-old cows. The relationship of pregnancy rate with age appears to be correlated with the BCS decrease at breeding in the older cows, supported by the fact that inclusion of BCS at breeding in the statistical model eliminated the effect of age on pregnancy rate (P = 0.42). Calving interval was longer in 3-yr-old cows compared with 4- to 9-yr-old cows (P = 0.02) however, among older cows, there was little change in the calving interval. Birth weight reached a maximum at 8 yr of age (35 +/- 0.9 kg) and a minimum in 3-yr-old cows (32 +/- 0.7 kg). Birth weights of calves born to both 3- and 4-yr-old cows were lower than for those born to 5-, 6-, 7-, or 8-yr-old cows (P < 0.05). Ten-year-old cows weaned lighter calves (205-d adjusted weaning weight) than younger dams. Furthermore, 3-yr-old cows weaned calves 9 +/- 2.1 and 14 +/- 2.4 kg lighter than 4- and 5-yr-old cows, respectively (P < 0.001). Interpretation of the age analyses of calving interval, birth weight, and weaning weight was independent of the inclusion of BCS in the model. This study documents the effects of age on calving interval, birth weight, and weaning weight that are independent of BCS.
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