Beef Industry Center

Armidale, Australia

Beef Industry Center

Armidale, Australia
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Marsh K.J.,Australian National University | Yin B.,Australian National University | Singh I.P.,National Institute of Pharmaceutical Education and Research | Saraf I.,National Institute of Pharmaceutical Education and Research | And 5 more authors.
Journal of Chemical Ecology | Year: 2015

Identifying specific plant secondary metabolites that influence feeding behavior can be challenging, but a solid understanding of animal preferences can guide efforts. Common brushtail possums (Trichosurus vulpecula) predominantly eat Eucalyptus species belonging to the subgenus Symphyomyrtus, and avoid eating those belonging to the Monocalyptus subgenus (also called subgenus Eucalyptus). Using an unbiased 1H NMR metabolomics approach, a previous study identified unsubstituted B ring flavanones in most species of monocalypts examined, whereas these compounds were absent from symphyomyrtles. We hypothesised that unsubstituted B ring flavanones act as feeding deterrents for common brushtail possums. In the current study, we tested this hypothesis by comparing how much possums ate of a basal diet, with diets containing one of four structurally related compounds; pinocembrin, flavanone (unsubstituted B ring flavanones), chrysin (the flavone analogue of pinocembrin), and naringenin (a flavanone with B ring substitution). We found that pinocembrin and flavanone deterred feeding relative to the basal diet, but that chrysin and naringenin did not at equivalent concentrations. Thus, unsubstituted B-ring flavanones may explain why brushtail possums avoid eating monocalypt species. Furthermore, small differences in the structure of secondary compounds can have a large impact on antifeedant properties. These results demonstrate that metabolomics can be a valuable tool for ecologists seeking to understand herbivore feeding preferences. © 2015, Springer Science+Business Media New York.


Donoghue K.A.,University of New England of Australia | Donoghue K.A.,Agricultural Research Center | Arthur P.F.,University of New England of Australia | Arthur P.F.,Elizabeth Macarthur Agricultural Institute | And 4 more authors.
Animal Production Science | Year: 2011

Angus cattle that had been divergently selected for Low and High post-weaning residual feed intake (RFI) were used in two projects to evaluate early-life reproductive performance and onset of puberty in females. In the first project, data on the 1999-born females (n = 64) were evaluated for weight, subcutaneous fat (P8 fat depth) and reproductive performance over two breeding cycles. These females that were the result of 1.0-2.5 (mean of 1.8) generations of selection, had mean (±s.e.) post-weaning RFI of -0.82 ± 0.19 kg/day and 0.57 ± 0.18 kg/day for the Low and High RFI selection lines, respectively. In the second project, ultrasonography was used to scan the ovaries of the 2008-born heifers (n = 121) on four occasions following weaning. In these heifers the presence of corpus luteum provided evidence of ovulation, and hence the commencement of onset of puberty. The average of the estimated breeding value (EBV) for RFI of the parents of the Low RFI and the High RFI selection line heifers were -0.72 ± 0.05 and 0.37 ± 0.03 kg/day, respectively. In the first project, no significant selection line differences were evident for weight, age at first mating, pregnancy and calving rates (percentage of females that were pregnant, or the percentage that calved out of the total number used for mating), calf birthweight and weight of calf born per female exposed to bull. Females from the Low RFI line had significantly (P < 0.05) lower P8 fat depth relative to their High RFI contemporaries at most of the measurement dates (e.g. 9.2 ± 0.5 versus 12.0 ± 0.5 mm at the start of first mating). Low RFI females also calved significantly (P < 0.05) later in the calving season than High RFI females (35.7 ± 3.0 versus 27.6 ± 2.4 days). The results indicate that there is a delayed pregnancy date during the first mating season leading to a later calving date for the Low RFI heifers. The later first calving date was then maintained at subsequent calving. The later calving, however, did not impact on pregnancy and calving rates. In the second project, it was observed that irrespective of selection line, heifers that had attained onset of puberty had significantly (P < 0.05) greater P8 fat depth than those that had not. Hence the expectation was that, relative to High RFI heifers, the Low RFI heifers with their lower P8 fat, will attain onset of puberty at a slightly older age. This expected trend was observed but the difference was not significant, and further investigations are recommended. © CSIRO 2011.


Cafe L.M.,University of New England of Australia | Cafe L.M.,Beef Industry Center | Robinson D.L.,University of New England of Australia | Robinson D.L.,Beef Industry Center | And 6 more authors.
Journal of Animal Science | Year: 2011

Relationships between temperament and a range of performance, carcass, and meat quality traits in young cattle were studied in 2 experiments conducted in New South Wales (NSW) and Western Australia (WA), Australia. In both experiments, growth rates of cattle were assessed during backgrounding on pasture and grain finishing in a feedlot. Carcass and objective meat quality characteristics were measured after slaughter. Feed intake and efficiency during grain finishing were also determined in NSW. Brahman (n = 82 steers and 82 heifers) and Angus (n = 25 steers and 24 heifers) cattle were used in the NSW experiment. In NSW, temperament was assessed by measuring flight speed [FS, m/s on exit from the chute (crush)] on 14 occasions, and by assessing agitation score during confinement in the crush (CS; 1 = calm to 5 = highly agitated) on 17 occasions over the course of the experiment. Brahman (n = 173) and Angus (n = 20) steers were used in the WA experiment. In WA, temperament was assessed by measuring FS on 2 occasions during backgrounding and on 2 occasions during grain feeding. At both sites, a hormonal growth promotant (Revalor-H, Virbac, Milperra, New South Wales, Australia) was applied to one-half of the cattle at feedlot entry, and the Brahman cattle were polymorphic for 2 calpain-system markers for beef tenderness. Temperament was not related (most P > 0.05) to tenderness gene marker status in Brahman cattle and was not (all P > 0.26) modified by the growth promotant treatment in either breed. The Brahman cattle had greater individual variation in, and greater correlations within and between, repeated assessments of FS and CS than did the Angus cattle. Correlations for repeated measures of FS were greater than for repeated assessments of CS, and the strength of correlations for both declined over time. Average FS or CS for each experiment and location (NSW or WA × backgrounding or finishing) were more highly correlated than individual measurements, indicating that the average values were a more reliable assessment of cattle temperament than any single measure. In Brahman cattle, increased average FS and CS were associated with significant (P < 0.05) reductions in backgrounding and feedlot growth rates, feed intake and time spent eating, carcass weight, and objective measures of meat quality. In Angus cattle, the associations between temperament and growth rates, feed intake, and carcass traits were weaker than in Brahmans, although the strength of relationships with meat quality were similar. © 2011 American Society of Animal Science. All rights reserved.


Cafe L.M.,University of New England of Australia | Cafe L.M.,Beef Industry Center | McIntyre B.L.,University of New England of Australia | McIntyre B.L.,Western Australian Department of Agriculture and Food | And 7 more authors.
Journal of Animal Science | Year: 2010

Experiments were conducted concurrently at 2 locations to quantify effects and interactions of calpain-system tenderness gene markers on growth, efficiency, temperament, and carcass traits of Brahman cattle. Cattle were selected at weaning from commercial and research herds based on their genotype for commercially available calpastatin (CAST) and calpain 3 (GAPN3) gene markers for beef tenderness. Genotypes for μ-calpain gene markers (CAPN1-4751 and GAPN1-316) were also determined and included in statistical analyses. The New South Wales (NSW) herd was composed of 82 heifers and 82 castrated male cattle with 0 or 2 favorable alleles for CAST and CAPN3. The Western Australia (WA) herd was composed of 173 castrated male cattle with 0, 1, or 2 favorable alleles for CAST and CAPN3. One-half of the cattle at each site were implanted with a hormonal growth promotant (HGP: Revalor-H) during grain finishing. Cattle were backgrounded at pasture for 6 to 8 mo and grain-fed for 117 d (NSW) or 80 d (WA) before slaughter. Individually, or in combination with each other and with CAPN1-4751 status, CAST and CAPN3 status had no significant (all P > 0.05) effects on BW, growth, feed efficiency, or temperament traits. The only significant effect of CAST or CAPN3 on carcass characteristics was a small increase in rib fat with increasing number of favorable CAST alleles (P = 0.042) in the WA herd. There were no significant interactions (all P > 0.05) between the markers, or between the markers and sex or HGP treatment apart from CAST × HGP for area of the M. longissimus lumborum (P = 0.024) in the NSW experiment. Favorable CAST or CAPN3 alleles appear unlikely to have detrimental effects on growth, efficiency, temperament, or carcass characteristics of Brahman cattle; however, some effects evident for CAPN1 status indicate the need for further production studies on effects of these markers. Overall, the findings of the present study indicate that calpain-system gene markers are suitable for use in marker-assisted selection to improve meat tenderness in Brahman cattle without negative effects on other production and carcass characteristics. © 2010 American Society of Animal Science.


Cafe L.M.,University of New England of Australia | Cafe L.M.,Beef Industry Center | Robinson D.L.,University of New England of Australia | Robinson D.L.,Beef Industry Center | And 5 more authors.
Domestic Animal Endocrinology | Year: 2011

Associations between temperament, stress physiology, and productivity were studied in yearling Brahman steers (n = 81). Steers differed in calpain system gene marker status; 41 were implanted with a hormonal growth promotant at feedlot entry. Temperament was assessed with repeated measurements of flight speed (FS) and crush score (CS) during 6 mo of backgrounding at pasture and 117 d of grain finishing. Adrenal responsiveness was assessed with ACTH challenge, with plasma samples collected immediately before and 60 min after challenge. Steers with higher FS and CS had higher prechallenge plasma cortisol, glucose, lactate, and nonesterified fatty acid concentrations. The ACTH-induced cortisol response was unrelated to FS or CS, but glucose remained higher after challenge in flightier steers. The hormonal growth promotant reduced adrenal responsiveness; tenderness genotype had no effect. When temperament assessments and cortisol concentrations before and after challenge were combined in a principal components analysis, four vectors accounting for 38%, 25%, 18%, and 9% of the variation were identified. The first vector had significant loadings on temperament and prechallenge cortisol; increasing scores were associated with increased plasma glucose, lactate, and nonesterified fatty acid and with reductions in BW and feedlot growth rates, carcass fatness, and muscle pH. The second vector loaded only on ACTH-induced cortisol response; increased scores related to increased residual feed intake, number of daily feed sessions, and meat marbling score. The third and fourth vectors had different loadings on FS and CS and appeared to identify different aspects of temperament measured by FS or CS. Fewer associations were found between the third or fourth vectors and productivity traits, possibly because of lower variance accounted for by these vectors. In conclusion, temperament was related to prechallenge cortisol but not to ACTH-induced cortisol response. Principal components analysis separated these traits into separate components, which in turn had different relations with productivity traits. The largest component of temperament was described similarly by FS and CS, but there were smaller components that these described differently. There were some temperament-related differences in the metabolic status of the steers which were not related to the variation in cortisol, suggesting involvement of the sympatho-adrenal-medullary axis in these temperament-related effects. © 2011 Elsevier Inc.


Robinson D.L.,Sheep Industry Cooperative Research Center | Robinson D.L.,Beef Industry Center | Goopy J.,Sheep Industry Cooperative Research Center | Goopy J.,Beef Industry Center | And 2 more authors.
Animal Production Science | Year: 2010

Rumen cannulated sheep (n = 12) were tested at each of three feeding levels: 0.8, 1.24 and 1.6 times maintenance. The ration (lucerne chaff) was provided in eight equal portions to emulate morning and afternoon grazing. After at least 10 days adaptation to each feeding level, methane production was measured in an open circuit calorimeter for 22 h using the same feeding regime. During measurement, 10 rumen samples were taken for volatile fatty acid (VFA) analysis by an indwelling rumen probe with a sampling tube that passed outside the calorimeter. Feed intake was strongly correlated with daily methane production (DMP, r = 0.87). Both methane production and VFA concentrations showed bimodal patterns related to the feeding cycle, but feed intake had a much smaller effect on VFA concentrations than on methane production rate. Average VFA concentration was a poor predictor of DMP. The best predictor, propionate concentration, explained 26% of the variance in DMP. The weakness of the association between VFA concentrations and methane production could be a consequence of differences in rumen volume and differences in VFA absorption associated with feeding level, although the possibility of accumulation of alternate fermentation end products or re-fermentation of VFA cannot be excluded. It is concluded that none of the suite of VFA parameters assessed offers a useful tool to predict daily methane production in grazing sheep. © 2010 CSIRO.


Bird S.H.,Beef Industry Center | Hegarty R.S.,Beef Industry Center | Woodgate R.,Beef Industry Center
Animal Production Science | Year: 2010

Three experiments were conducted to evaluate routes by which viable rumen ciliate-protozoa may be transferred between mature sheep. Feed, water and faecal material were tested as possible vectors for protozoal transfer in addition to direct animal to animal contact. In Experiment 1, protozoa-free sheep were either offered or orally dosed with protozoa-contaminated material or allowed contact with faunated animals. The treated sheep were then monitored over a 4-week period for the appearance of protozoa in the rumen. Protozoa were successfully transferred to protozoa-free animals via contaminated water but no transfer occurred via feed or faeces or by direct animal to animal contact. In Experiment 2, the drinking water of penned faunated sheep was found to become contaminated with protozoa within 46 h of being placed in the pen. In Experiment 3, nine protozoa-free sheep were grazed in a paddock with a flock of 75 faunated ewes for periods of 13 weeks, and protozoa became established in one protozoa-free sheep. The results of these studies suggest that the most likely mode of transfer of protozoal cells from one sheep to another is via water, rather than by rumen fluid contaminating feed, or from faeces of faunated sheep. Further tests are required to demonstrate protozoal transmission via water occur under a range of conditions and inoculum levels. © 2010 CSIRO.


Pollock K.S.,Beef Industry Center
Journal of agricultural safety and health | Year: 2012

Farm-related fatalities are a significant problem in Australian agriculture. Over the period 2001-2004, there were 404 fatalities that occurred as a direct consequence of visiting, residing, or working on a farm. This study employed a human capital approach to establish the economic costs of farm-related fatalities to the Australian economy. Modeling of direct and indirect costs associated with farm-related fatalities estimated that the 404 traumatic deaths over the period 2001-2004 cost the Australian economy $650.6 million in 2008 Australian dollars (AUD). This equates to 2.7% of the 2008 farm gross domestic product (GDP) due to potentially preventable farm accidents and injuries. Farm-related deaths are a significant economic cost to the Australian economy. Greater resources need to be directed to farm health and safety interventions to increase their effectiveness at reducing the risk exposure of those visiting, residing, and working on Australian farms.


PubMed | Beef Industry Center
Type: Journal Article | Journal: Journal of agricultural safety and health | Year: 2012

Farm-related fatalities are a significant problem in Australian agriculture. Over the period 2001-2004, there were 404 fatalities that occurred as a direct consequence of visiting, residing, or working on a farm. This study employed a human capital approach to establish the economic costs of farm-related fatalities to the Australian economy. Modeling of direct and indirect costs associated with farm-related fatalities estimated that the 404 traumatic deaths over the period 2001-2004 cost the Australian economy $650.6 million in 2008 Australian dollars (AUD). This equates to 2.7% of the 2008 farm gross domestic product (GDP) due to potentially preventable farm accidents and injuries. Farm-related deaths are a significant economic cost to the Australian economy. Greater resources need to be directed to farm health and safety interventions to increase their effectiveness at reducing the risk exposure of those visiting, residing, and working on Australian farms.


PubMed | Beef Industry Center
Type: Journal Article | Journal: Animal genetics | Year: 2011

Feed efficiency is an economically important trait in beef production. It can be measured as residual feed intake. This is the difference between actual feed intake recorded over a test period and the expected feed intake of an animal based on its size and growth rate. DNA-based marker-assisted selection would help beef breeders to accelerate genetic improvement for feed efficiency by reducing the generation interval and would obviate the high cost of measuring residual feed intake. Although numbers of quantitative trait loci and candidate genes have been identified with the advance of molecular genetics, our understanding of the physiological mechanisms and the nature of genes underlying residual feed intake is limited. The aim of the study was to use global gene expression profiling by microarray to identify genes that are differentially expressed in cattle, using lines genetically selected for low and high residual feed intake, and to uncover candidate genes for residual feed intake. A long-oligo microarray with 24 000 probes was used to profile the liver transcriptome of 44 cattle selected for high or low residual feed intake. One hundred and sixty-one unique genes were identified as being differentially expressed between animals with high and low residual feed intake. These genes were involved in seven gene networks affecting cellular growth and proliferation, cellular assembly and organization, cell signalling, drug metabolism, protein synthesis, lipid metabolism, and carbohydrate metabolism. Analysis of functional data using a transcriptional approach allows a better understanding of the underlying biological processes involved in residual feed intake and also allows the identification of candidate genes for marker-assisted selection.

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