ORCID Profile
0000-0003-4898-2843
Current Organisation
University of Queensland - Gatton Campus
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Publisher: Springer Science and Business Media LLC
Date: 25-03-2019
DOI: 10.1007/S00484-019-01711-3
Abstract: When exposed to hot conditions, heat dissipation via an increase in respiration rate (RR) is an important thermoregulatory mechanism for sheep. However, evaluating RR under field conditions is difficult. In cattle, a viable alternative has been to assess panting score (PS) therefore, the objective of this study was to evaluate the relationship between RR and PS to determine if a PS index can be used to evaluate heat load in sheep. One hundred and forty-four Merino wethers (44.02 ± 0.32 kg) were used within a climate-controlled study. The study was replicated twice over 29 days, where each replicate consisted of two treatments: (1) thermoneutral (TN) and (2) hot (HOT). Ambient temperature (T
Publisher: Springer Science and Business Media LLC
Date: 23-03-2017
DOI: 10.1007/S00484-017-1309-1
Abstract: Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue s les processed for evidence of histopathology. Radio transmitters were less reliable than DLs RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT (r > 0.94, P 0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.
Publisher: MDPI AG
Date: 06-06-2019
DOI: 10.3390/ANI9060322
Abstract: Heat stress and cold stress have a negative influence on cattle welfare and productivity. There have been some studies investigating the influence of cold stress on cattle, however the emphasis within this review is the influence of heat stress on cattle. The impact of hot weather on cattle is of increasing importance due to the changing global environment. Heat stress is a worldwide phenomenon that is associated with reduced animal productivity and welfare, particularly during the summer months. Animal responses to their thermal environment are extremely varied, however, it is clear that the thermal environment influences the health, productivity, and welfare of cattle. Whilst knowledge continues to be developed, managing livestock to reduce the negative impact of hot climatic conditions remains somewhat challenging. This review provides an overview of the impact of heat stress on production and reproduction in bovines.
Publisher: Springer Science and Business Media LLC
Date: 14-01-2022
Publisher: Springer Science and Business Media LLC
Date: 20-10-2017
DOI: 10.1007/S00484-017-1459-1
Abstract: Animal biometeorology (insects excluded) has been part of the International Journal of Biometeorology since its inception in 1958. Over the first 60 years of the journal, 480 animal biometeorology papers were published. Thus, approximately 14% of published papers dealt with animals. Over the first 60 years, data from more than 50 animal species was presented, with the lead authors coming from 48 countries. The two most common species used in animal papers between 1957 and 2016 were cattle (109 papers: 22.7% of all animal papers) and rats (96 papers: 20.0% of all animal papers). Although cattle and rats dominated, the species in the most cited paper (240 citations) was chickens, followed by bird migration (155 citations), and general livestock (118 citations). Overall, five papers exceeded 100 citations, and a further two exceeded 200 citations. In the last decade, 126 animal papers were published (26% of all animal papers). Many of these papers had a focus on livestock production in developing countries especially Brazil.
Publisher: Springer Science and Business Media LLC
Date: 06-07-2017
DOI: 10.1007/S00484-019-01735-9
Abstract: Livestock industries have an important role in ensuring global food security. This review discusses the importance of quantifying the heat stress response of ruminants, with an emphasis on identifying thermo-tolerant breeds. There are numerous heat stress prediction models that have attempted to quantify the response of ruminant livestock to hot climatic conditions. This review highlights the importance of investigating prediction models beyond the temperature-humidity index (THI). Furthermore, this review highlights the importance of incorporating other climatic variables when developing prediction indices to ensure the accurate prediction of heat stress in ruminants. Prediction models, particularly the heat load index (HLI) were developed to overcome the limitations of the THI by incorporating ambient temperature (AT), relative humidity (RH), solar radiation (SR) and wind speed (WS). Furthermore refinements to existing prediction models have been undertaken to account for the interactions between climatic variables and physiological traits of livestock. Specifically, studies have investigated the relationships between coat characteristics, respiration rate (RR), body temperature (BT), sweating rate, vasodilation, body weight (BW), body condition score (BCS), fatness and feed intake with climatic conditions. While advancements in prediction models have been occurring, there has also been substantial advancement in the methodologies used to quantify animal responses to heat stress. The most recent development in this field is the application of radio frequency identification (RFID) technology to record animal behaviour and various physiological responses. Rumen temperature measurements using rumen boluses and skin temperature recording using infrared thermography (IRT) are making inroads to redefine the quantification of the heat stress response of ruminants. Further, this review describes several advanced biotechnological tools that can be used to identify climate resilient breeds of ruminant livestock.
Publisher: Informa UK Limited
Date: 02-01-2018
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN19689
Abstract: Context Approximately 2 million sheep are exported from Australia on live export voyages annually. As voyages travel from a southern hemisphere winter to a northern hemisphere summer, production and welfare issues associated with excessive heat load may arise. Aims The aim of this study was to evaluate the responses of sheep to incremental heat load under simulated live export conditions, specifically the influence of heat load on the metabolic and inflammatory status of sheep. Methods A total of 144 Merino wethers (44.02 ± 0.32 kg) were used in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral, and (2) hot. Sheep in the hot treatment were exposed to heat load simulated from live export voyages from Australia to the Middle East. Blood s les were collected from all sheep (n = 144) on Day 1, then at 7-day intervals (n = 5) for the duration of each 29-day period. Blood s les were analysed to determine the cytokine, biochemistry and haematology (data not presented here) profiles. Cytokine and biochemical profiles were analysed using a repeated measures model assuming a compound symmetry covariance. The model fitted included terms for cohort and treatment (hot, thermoneutral), and a term for s le collection day (day) and a treatment × day interaction. The subject factor corresponded to the cohort × treatment combinations. Key results There were no consistent trends in plasma cytokine and biochemical profiles. Bicarbonate was the only parameter that was influenced by cohort (P = 0.0035), treatment (P = 0.0025), collection (P = 0.0001) and treatment × collection (P = 0.0025). Furthermore, interleukin-6 and glutamate dehydrogenase were the only parameters that were not influenced by cohort (P & 0.295), treatment (P = 0.2567), collection (P & 0.06) or treatment × collection (P = 0.34). Conclusions Overall, these data highlight that the metabolic and inflammatory status of sheep exposed to incremental heat load, during a simulated live export voyage from a southern hemisphere winter to a northern hemisphere summer, were not markedly altered. Implications These results provide a preliminary evaluation of the inflammatory and metabolic status of sheep on arrival in the Middle East.
Publisher: Wiley
Date: 05-2015
DOI: 10.1111/AVJ.12308
Abstract: An 18-month-old Charolais steer was presented with lameness and fluctuant swelling of the right stifle joint, which yielded neutrophils on fine-needle aspiration. A diagnosis of bacterial proliferative tenosynovitis and arthritis was made on postmortem and histological examination. Culture and 16S rRNA sequencing identified a Nocardia sp. with 99% homology with the corresponding DNA fragment of N. mexicana DSM 44952. Antimicrobial susceptibility testing revealed the isolate was susceptible to co-trimoxazole and third-generation cephalosporins. We report the first case, both in Australia and internationally, of proliferative tenosynovitis and arthritis caused by Nocardia spp. infection in a bovine and the first report of pathology attributed to N. mexicana in a veterinary patient. Given the limited susceptibility of the bacteria, the poor antimicrobial penetration that would be expected and the morphological changes that had taken place in the joint the steer would have required protracted antimicrobial treatment in addition to invasive debridement of the lesion. This case emphasises the importance of routinely performing cytology and extended incubation of cultures in cases of arthritis in order to make ethical and economically viable treatment decisions.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN19621
Abstract: The rising global demand for animal protein is leading to intensification of livestock production systems. At the same time, societal concerns about sustainability and animal welfare in intensive systems is increasing. This review examines the risks to welfare for beef cattle within commercial feedlots in Australia. Several aspects of the feedlot environment have the potential to compromise the physical and psychological welfare of cattle if not properly monitored and managed. These include, but are not limited to, animal factors such as the influence of genetics, temperament and prior health, as well as management factors such as diet, pen design, resource provision, pregnancy management, and stock-person attitudes and skills. While current industry and producer initiatives exist to address some of these issues, continuous improvements in welfare requires accurate, reliable and repeatable measures to allow quantification of current and future welfare states. Existing measures of welfare are explored as well as proxy indicators that may signal the presence of improved or reduced welfare. Finally, potential future measures of welfare that are currently under development are discussed and recommendations for future research are made.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN19687
Abstract: Context Annually, millions of sheep are exported from Australia to the Middle East, typically during the southern hemisphere winter to the northern hemisphere summer. During these voyages, sheep can be exposed to relatively rapid changes in ambient conditions within a short period of time (≤29 days) therefore, excessive heat load concerns can arise. Aims The aim of this study was to define the responses of sheep to incremental heat load under simulated live export conditions. The study herein describes (1) the heat load imposed, and (2) the effect of this heat load on the growth, performance and behavioural responses of sheep during periods of incremental heat load. Methods A total of 144 Merino wethers (44.02 ± 0.32 kg) were included in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral and (2) hot (HOT). Ambient temperature (°C) and relative humidity (%) for the HOT treatment were modelled from live export voyages from Australia to the Middle East in July. Climatic conditions within the climate control chambers were recorded at 10-min intervals, then used to calculate a temperature humidity index. Sheep posture, rumination, eating, drinking and demeanour (calm, agitated or depressed) were observed four times daily at 3-h intervals between 0800 hours and 1700 hours. Feed intake was recorded daily and water intake was measured using an automated meter. Sheep were weighed on Day 0 and then at 7-day intervals. Sheep were weighed at slaughter and carcass weights were obtained, these data were used to determine carcass dressing percentage. Data were analysed using a repeated measures model, with a compound symmetry covariance structure. Key results Climatic conditions in the HOT treatment increased incrementally between Day 1 (temperature humidity index ≥19) and Day 29 (temperature humidity index ≤34.7). Behaviour, feed intake, average daily gain (g/day), carcass weight (kg) and dressing percentage were not influenced by treatment (P & 0.05). Sheep in the HOT treatment group showed a 137% increase in water intake (P & 0.01) and on average consumed 2.15 L/sheep.day, whereas the thermoneutral group consumed 1.67 L/sheep.day. Conclusions These results suggest that these sheep were capable of maintaining feed intake and growth despite exposure to heat load, albeit with a 137% increase in water intake. Implications These results highlight the resilience of the Australian Merino genotype, as these sheep were capable of maintaining feed intake and growth during exposure to heat load. As the climatic conditions in this study were modelled based on typical live export vessel conditions, these results may suggest that the climatic conditions experienced by sheep during voyages may not be as critical as previously thought.
Publisher: Springer Science and Business Media LLC
Date: 16-09-2017
DOI: 10.1007/S00484-017-1442-X
Abstract: Thirty-six steers (12 of each Angus, Charolais, and Brahman) with an initial BW of 318.5 ± 6.7 kg were used in a 130-day study. Two treatments were imposed: un-shaded and shaded (3 m
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.RVSC.2019.08.011
Abstract: Heat stress is well documented to have a negative influence on livestock productivity and these impacts may be exacerbated by climate change. Dairy cattle can be more vulnerable to the negative effects of heat stress as these adverse impacts may be more profound during pregnancy and lactation. New emerging diseases are usually linked to a positive relationship with climate change and the survival of microrganisms and/or their vectors. These diseases may exaggerate the immune suppression associated with the immune suppressive effect of heat stress that is mediated by the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal-medullary (SAM) axes. It has been established that heat stress has a negative impact on the immune system via cell mediated and humoral immune responses. Heat stress activates the HPA axis and increases peripheral levels of glucocorticoids subsequently suppressing the synthesis and release of cytokines. Heat stress has been reported to induce increased blood cortisol concentrations which have been shown to inhibit the production of cytokines such as interleukin-4 (IL-4), IL-5, IL-6, IL-12, interferon γ (IFNγ), and tumor necrosis factor-α (TNF- α). The impact of heat stress on the immune responses of dairy cows could be mediated by developing appropriate amelioration strategies through nutritional interventions and cooling management. In addition, improving current animal selection methods and the development of climate resilient breeds may support the sustainability of livestock production systems into the future.
Publisher: University of Queensland Library
DOI: 10.14264/UQL.2016.99
Publisher: Springer Science and Business Media LLC
Date: 09-03-2017
DOI: 10.1007/S00484-017-1315-3
Abstract: The bull's scrotum and scrotal cord vasculature has traditionally been regarded as a thermoregulatory device for maintaining optimal testicular temperature for normal spermatogenesis. This assumption has mostly been derived from discrete measurements using thermocouples with limited data correlating continuous scrotal temperature (ST) to body temperature (BT). From mid-summer to early autumn, four Wagyu bulls (9-18 months) were surgically implanted with two data loggers (DL) logging at 30 min intervals: one on the right hand side flank and the other was attached to the visceral vaginal tunic of the mid-testis. Bulls were firstly housed in a paddock (PK) for 13 days and then moved to in idual pens (IP), again for 13 days. Repeated measures analysis modelled the long-term and diurnal trends in BT and ST. While both day and time of day (TOD) were significant effects for ST at both housing locations (P < 0.005), only TOD showed significance for BT at both locations (P < 0.0001). Significant effects were seen between bulls with ST (F = 167.2, P < 0.001) but not BT (F = 0.03, P = 0.863), suggestive of variation in in idual bull thermoregulatory capacity. Dual peaks were observed in ST at 0500 and 2130 h when housed in PK but not IP, suggesting ST may be influenced by external stimuli such as postural or behavioural changes. Reporting concurrent and continuous BT and ST will allow further investigation into factors influencing bovine ST and should be useful in selecting bulls with high degrees of thermoregulation capacity.
Publisher: American Dairy Science Association
Date: 09-2020
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN19013
Abstract: Context Feedlot cattle can be negatively impacted by hot conditions, such that they have reduced performance and wellbeing. This study was conducted at the research feedlot located at The University of Queensland during a southern hemisphere summer (October to April). Aims The objective of this study was to evaluate the influence of shade on the behaviour and panting score of Bos taurus and Bos indicus feedlot cattle during summer. Methods Thirty-six steers (12 Angus, 12 Charolais and 12 Brahman) with an initial non-fasted liveweight of 318.5 ± 6.7 kg were used in a 154-day feedlot study consisting of two treatments: unshaded and shaded (3 m2/animal). Observational data were obtained for each steer at 2 h intervals between 0600 and 1800 hours daily from Day 1 to Day 154. Additional night time observational data were collected at 2-h intervals between 2000 and 0400 hours on 12 occasions. Data collected included activity (feeding, drinking, or ruminating), posture (standing or lying) and panting score. Panting scores were used to calculate a mean panting score for each breed × treatment group. Observational data were converted to a count for each breed × treatment group for each observation time point and were analysed using a binomial generalised linear model. Key results Maximum shade utilisation was the greatest at 1200 hours for Angus (85.5%), Charolais (32.7%) and Brahman (33.3%) steers. All breed × treatment groups exhibited a notable increase in mean panting score as heat load increased. Average increase in mean panting score was 0.36, where shaded Brahman exhibited the smallest increase (0.13) and unshaded Angus had the greatest increase (0.71). When heat load conditions were very hot (heat load index (HLI) ≥ 86) the mean panting score of all breed × treatment groups differed (P & 0.05). Conclusions Overall these results emphasise the importance of providing shade to feedlot cattle, irrespective of genotype. Implications These results further highlight the importance of providing shade to feedlot cattle. These results challenge the general perception that Bos indicus feedlot cattle do not require access to heat load alleviation strategies.
Publisher: Springer Singapore
Date: 2017
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN20268
Abstract: Context Australia exports ~2 million sheep annually. On these voyages, sheep can be exposed to rapidly changing ambient conditions within a short time, and sheep may be exposed to periods of excessive heat load. Aims The aim of this study was to define the responses of sheep exposed to incremental heat load under simulated live export conditions. The study herein describes the influence of heat load on wool surface temperature, body temperature (rumen temperature (TRUM), °C and rectal temperature (TREC), °C) and respiratory dynamics (respiration rate, breaths/min and panting score (PS)) of sheep under live export conditions. In addition, the relationship between body temperature and respiratory dynamics was investigated. Methods A total of 144 Merino wethers (44.02 ± 0.32 kg) were used in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral (TN ambient temperature was maintained between 18°C and 20°C), and (2) hot (HOT ambient temperature minimum and maximum were 22.5°C and 38.5°C respectively). Sheep in the HOT treatment were exposed to heat load simulated from live export voyages from Australia to the Middle East. Respiration rate, PS and wool surface temperature (°C) data were collected four times daily, at 3-h intervals between 0800 hours and 1700 hours. Rectal temperatures were collected on five occasions at 7-day intervals. These data were evaluated using a repeated measures model, assuming a compound symmetry covariance structure. In idual TRUM were obtained via rumen boluses at 10-min intervals between Days 23 and 29 of Cohort 2. In idual TRUM data were collated and converted to an hourly mean TRUM for each sheep, these data were then used to determine the hourly mean TRUM for TN and HOT, then analysed using a first order autoregressive repeated measures model. Additionally, the relationship between respiratory dynamics and TRUM were investigated using a Pearson’s correlation coefficient, a partial correlation coefficient and a multivariate analysis of variance. Key results The respiration rate of the HOT sheep (140 ± 3.55 breaths/min) was greater (P & 0.01) than that of the TN sheep (75 ± 3.55 breaths/min). Similarly, the PS of the HOT (1.5 ± 0.02) sheep was greater (P = 0.009) compared with the TN sheep (1.2 ± 0.02). Wool surface temperatures and TREC were greater (P & 0.05) for the HOT sheep than for the TN sheep. There were treatment (P & 0.0001), hour (P & 0.0001), day (P = 0.038) and treatment × hour (P & 0.0001) effects on the TRUM of TN and HOT sheep. Conclusions The climatic conditions imposed within the HOT treatment were sufficient to disrupt the thermal equilibrium of these sheep, resulting in increased respiration rate, PS, TREC and TRUM. Implications These results suggest that the sheep were unable to completely compensate for the imposed heat load via respiration, thus resulting in an increase in TREC and TRUM.
Publisher: Springer Science and Business Media LLC
Date: 13-03-2019
DOI: 10.1007/S00484-019-01706-0
Abstract: This study was conducted to determine the relationship between rectal temperature (T
Publisher: MDPI AG
Date: 10-02-2021
DOI: 10.3390/ANI11020474
Abstract: The aim of this study was to evaluate the effect of carcass traits, lairage time and weather conditions during lairage and abattoir factors that impact the incidence of dark cutting in 142,228 grain-fed carcasses, as defined by Meat Standards Australia (MSA) guidelines. This study was conducted over a 12-month period analysing data from cattle that were supplied from seven feedlots and processed at three abattoirs. Abattoir data indicated that the average incidence of dark cutting within the study was 2.8%. Increased wind speeds (WSs) and rain during lairage at the abattoir was associated with an increased risk of dark cutting, whereas variation in ambient temperature and/or relative humidity did not influence dark cutting. Heavier carcasses with whiter fat, larger hump heights, more rib fat, higher marble scores and lower ossification had lower incidences of dark cutting. The factors abattoir, time in lairage, time to grading and grader within Abattoir had significant effects on the incidence of dark cutting. The results from this study suggest that reducing the time in lairage and increasing the time between slaughter and grading are the two major ways to reduce dark cutting in MSA carcasses.
Publisher: Springer Science and Business Media LLC
Date: 19-07-2017
DOI: 10.1007/S00484-017-1408-Z
Abstract: The International Society of Biometeorology (ISB) has covered significant breadth and depth addressing fundamental and applied societal and environmental challenges in the last 60 years. Biometeorology is an interdisciplinary science connecting living organisms to their environment, but there is very little understanding of the existence and placement of this discipline within formal educational systems and institutions. It is thus difficult to project the ability of members of the biometeorological community-especially the biometeorologists of the future-to help solve global challenges. In this paper, we ask: At present, how we are training people to understand and think about biometeorology? We also ask: What are the current tools and opportunities in which biometeorologists might address future challenges? Finally, we connect these two questions by asking: What type of new training and skill development is needed to better educate "biometeorologists of the future" to more effectively address the future challenges? To answer these questions, we provide quantitative and qualitative evidence from an educationally focused workshop attended by new professionals in biometeorology. We identify four common themes (thermal comfort and exposures, agricultural productivity, air quality, and urbanization) that biometeorologists are currently studying and that we expect to be important in the future based on their alignment with the United Nations Sustainable Development Goals. Review of recent literature within each of these thematic areas highlights a wide array of skill sets and perspectives that biometeorologists are already using. Current and new professionals within the ISB have noted highly varying and largely improvised educational pathways into the field. While variability and improvisation may be assets in promoting flexibility, adaptation, and interdisciplinarity, the lack of formal training in biometeorology raises concerns about the extent to which continuing generations of scholars will identify and engage with the community of scholarship that the ISB has developed over its 60-year history.
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/AN17776
Abstract: The temperature humidity index (THI) has been extensively used in the Australian dairy industry as an indicator of heat load conditions. However, there are limitations to the THI, where it does not account for solar radiation or wind speed. In addition, the THI has not been formulated in conjunction with physiological data. Thus, it is not apparent whether the THI provides the best prediction for impact of heat load on lactating dairy cattle. The aim of the present study was to develop a dairy heat load index (DHLI), based on the physiological responses of lactating dairy cows to environmental conditions. The study was undertaken at The University of Queensland, Gatton C us, Australia, over three summers and two winters. Observations were conducted four times daily at 0800 hours, 1200 hours, 1400 hours and 1700 hours. Weather data were obtained every 10 min from an onsite, automated weather station. Panting score data were used to calculate a mean panting score of the herd. Developing the DHLI encompassed three different modelling techniques, including (1) linear regression, (2) broken stick regression and (3) non-linear logistic regression. Comparisons between the models indicated there was an increase in accuracy when using non-linear logistic regression (R2 = 0.542). The DHLI model developed was based on mean panting score, black globe temperature (°C) and relative humidity. By utilising the black globe temperature, the DHLI is able to incorporate the combined effects of ambient temperature, relative humidity, solar radiation and wind speed in a single unit measure. By combining climatic conditions and a physiological response, i.e. panting score, the DHLI model may become a more accurate prediction of heat load for lactating dairy cows. The DHLI produces a unit value between 0 and 100. When DHLI is 0, there would be no panting and, when DHLI is 100, all cows within the herd would be panting.
Publisher: Springer Singapore
Date: 2017
Publisher: Frontiers Media SA
Date: 14-04-2016
Publisher: MDPI AG
Date: 08-08-2019
DOI: 10.3390/FOODS8080332
Abstract: Actinidin is a cysteine protease enzyme which occurs in kiwifruit and has been associated with improved tenderness in red meat. This study evaluated the impact of actinidin, derived from kiwifruit, on consumer sensory outcomes for striploin (M. longissimus lumborum) and outside flat (M. biceps femoris). Striploins and outside flats were collected from 87 grass-fed steers. Carcasses were graded to the Meat Standards Australia (MSA) protocols. Striploins and outside flats were then dissected in half and allocated to one of the following two treatments: (1) not infused (control) and (2) infused with a kiwifruit extract (enhanced), and then prepared as grill and roast s les. Grill and roast s les were then aged for 10 or 28 days. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 2080 in idual consumers, in accordance with the MSA protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Consumer sensory scores for tenderness, juiciness, flavor, overall liking, and MQ4 score were analyzed using a linear mixed-effects model. Kiwifruit extract improved consumer scores for tenderness, juiciness, flavor, overall liking, and MQ4 scores for striploins and outside flat (p 0.05). These results suggest that kiwifruit extract provides an opportunity to improve eating experiences for consumers.
Publisher: MDPI AG
Date: 20-01-2020
DOI: 10.3390/ANI10010172
Abstract: Previous studies have indicated that cattle with more excitable temperaments exhibit an increased stress response. The objective of this study was to investigate the relationship between temperament traits, handling, and stress-induced hyperthermia (SIH) in beef cattle. Rectal temperatures (TREC, °C) of 60 purebred Angus cattle (30 heifers, 30 steers 235.2 ± 5.11 kg) were recorded at 20 s intervals from 30 min prior to handling until two hours post handling. All cattle were exposed to a standardized handling procedure consisting of (i) being restrained in a weighing box for 30 s (ii) being held within the crush for 30 s and then (iii) being restrained in a head bail for 60 s. Cattle temperaments were evaluated via three traits: (1) agitometer score (AG) (2) crush score (CS) and (3) flight speed (FS) during the handling procedure. Agitometer scores and FS measures were used to describe an AG category (AGCAT) and an FS category (FSCAT) that were used to classify animals into three temperament categories: 1, calm 2, intermediate and 3, temperamental. Pearson’s correlation coefficients were used to evaluate the associations between (i) AG, CS, FS, and TREC 30 min prior to entry into the weighing box (T-30) and then at 1 min intervals between time of entry into the weighing box (T0) until 10 min post-weighing (T10) and (ii) the relationship between AG, CS, and FS. The relationship between TREC and temperament traits over the 2.5 h were modeled by using a first-order autoregressive repeated measures model. Flight speed had strong to moderate associations with TREC at T-30 (r ≥ 0.37 p ≤ 0.006) and between T0 and T10 (r ≥ 0.36 p ≤ 0.01). There were moderate associations amongst TREC between T0 and T10 and CS (r ≥ 0.31 p ≤ 0.01). A weak relationship existed with CS (r = 0.16 p = 0.16). There were no associations between AG and TREC at T-30 (r ≥ −0.15 p = 0.84) or between T0 and T10 (r ≤ 0.04 p ≥ 0.4). Rectal temperature, irrespective of sex and temperament traits, was influenced by time (p 0.0001), and maximum TREC (39.3 ± 0.04 °C) occurred between 4 and 5.7 min after entry into the weighing box. In addition, CS (p = 0.007) influenced TREC in these cattle. There were also time × temperament trait × sex interactions with the CS (p = 0.0003) and FSCAT (p = 0.043) categories however, time × temperament trait interactions were not statistically significant. Results from this study suggest that cattle with excitable temperaments, as evaluated by FS and CS, have a greater increase in TREC. In addition, these results suggest that a relationship exists between basal TREC and FS and CS. Together, these results highlight that temperament, as assessed by FS and CS, influences both basal TREC and the peak temperature recorded following handling but does not influence the magnitude of change in TREC post handling.
Publisher: Springer Science and Business Media LLC
Date: 11-09-2017
DOI: 10.1007/S00484-017-1433-Y
Abstract: Thirty-six Black Angus steers were used in a replicated study three replicates of 12 steers/replicate. Steers had an initial non-fasted BW of 392.3 ± 5.1, 427.5 ± 6.3, and 392.7 ± 3.7 kg for each replicate, respectively. Steers were housed outside in in idual animal pens (10 m × 3.4 m). Each replicate was conducted over a 6-day period where infrared thermography (IRT) images were collected at 3-h intervals, commencing at 0600 h on day 1 and concluding at 0600 h on day 6. Rumen temperatures (T
Publisher: Springer Singapore
Date: 2017
Publisher: MDPI AG
Date: 05-08-2022
DOI: 10.3390/ANI12151989
Abstract: It has been well-established that dark cutting (DC) is a multifactorial issue that is associated with numerous animal and management factors. However, there is limited understanding of the feedlot-based factors that contribute to the influence of DC. The aim of this study was to evaluate the effect of climate, animal, and feedlot factors on the incidence of pH non-compliance in Australian grain-fed cattle. For this study, feedlot and abattoir records from 142,228 in idual cattle over a 1-year period were investigated. These data incorporated records from seven feedlots that consigned cattle to three abattoirs. The average incidence of DC in these carcasses was 2.8%. The production factors that were associated with increased risk of DC included feedlot, sex, hormone growth promotants (HGP), cattle health, and days on feed (DOF). Additionally, DC also increased by reduced solar radiation (SR, W/m2), lower wind speeds (WS, m/s), increased ambient temperature (TA, °C), higher rainfall, a higher average temperature–humidity index (THI), and increased duration of time above heat-load-index threshold of 86 (HLI ≥ 86) during the 7 days prior to feedlot departure. This study identified the feedlot factors that increase the risk of DC from a feedlot-management perspective.
Publisher: American Meteorological Society
Date: 09-2017
Publisher: Elsevier BV
Date: 07-2020
Publisher: MDPI AG
Date: 18-09-2018
DOI: 10.3390/ANI8090156
Abstract: This study evaluated the relationship between rectal temperature (TREC, °C) and vaginal temperature (TVAG, °C) in grazing Bos taurus heifers, to develop an understanding of the reliability of these measures as estimates of core body temperature. Nineteen Angus heifers (BW = 232.2 ± 6.91 kg) were implanted with intra-rectal and intra-vaginal data loggers. Rectal temperature and TVAG were simultaneously recorded at 20 s intervals over 18.5 h. Heifers were housed as a singular cohort on grazing pastures for the duration of the study. A strong linear relationship (R2 = 0.72, p 0.0001) between the measurement sites was identified. The mean difference between TREC and TVAG was small, in which TVAG was on average 0.22 ± 0.01 °C lower than TREC. In idual twenty second TREC and TVAG data were used to determine the pooled mean TREC and TVAG and then to highlight the within measure variation over time. The coefficient of variation was, on average, lower (p 0.001) for TVAG (0.38%) than TREC (0.44%), indicating that TVAG exhibited less variation. Overall, the results from the current study suggest that a strong relationship exists between TREC and TVAG, and that TVAG may be a more reliable estimate of core body temperature than TREC in grazing Bos taurus heifers.
Location: Australia
No related grants have been discovered for Angela Lees.