scholarly journals Factors affecting the faecal P status of lactating beef cattle in Northern Australia

2015 ◽  
Author(s):  
W. J. Dollemore
Keyword(s):  
Beef Cattle ◽  
Northern Australia ◽  
Factors Affecting

scholarly journals Epidemiology and Management of BVDV in Rangeland Beef Breeding Herds in Northern Australia

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1063 ◽  
Author(s):  
Michael McGowan ◽  
Kieren McCosker ◽  
Geoff Fordyce ◽  
Peter Kirkland
Keyword(s):  
Beef Cattle ◽  
Reproductive Performance ◽  
Management Practices ◽  
Northern Australia ◽  
Routine Testing ◽  
Factors Affecting ◽  
Persistently Infected ◽  
Lactating Cows ◽  
The World ◽  
Intensively Managed

Approximately 60% of Australia’s beef cattle are located in the vast rangelands of northern Australia. Despite the often low stocking densities and extensive management practices of the observed herd, animal prevalence of BVDV infection and typical rates of transmission are similar to those observed in intensively managed herds in southern Australia and elsewhere in the world. A recent large three- to four-year study of factors affecting the reproductive performance of breeding herds in this region found that where there was evidence of widespread and/or recent BVDV infection, the percentage of lactating cows that became pregnant within four months of calving was reduced by 23%, and calf wastage was increased by 9%. BVDV is now considered the second most important endemic disease affecting beef cattle in northern Australia, costing the industry an estimated AUD 50.9 million annually. Although an effective killed vaccine was released in Australia in 2003, the adoption of routine whole herd vaccination by commercial beef farmers has been slow. However, routine testing to identify persistently infected replacement breeding bulls and heifers has been more widely adopted.

Factors affecting placental size in beef cattle: Maternal and fetal influences

2021 ◽  
Author(s):  
Colby A. Redifer ◽  
Natalie B. Duncan ◽  
Allison M. Meyer
Keyword(s):  
Beef Cattle ◽  
Factors Affecting

Some Factors Affecting Feed Utilization in Growing Beef Cattle

1955 ◽  
Vol 14 (4) ◽  
pp. 970-978 ◽  
Author(s):  
George Nelms ◽  
Ralph Bogart
Keyword(s):  
Beef Cattle ◽  
Feed Utilization ◽  
Factors Affecting

scholarly journals Factors affecting growth traits of beef cattle breeds raised inSlovakia

2011 ◽  
Vol 50 (No. 1) ◽  
pp. 14-21 ◽  
Author(s):  
E. Krupa ◽  
M. Oravcová ◽  
P. Polák ◽  
J. Huba ◽  
Z. Krupová
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Least Squares ◽  
Linear Model ◽  
Growth Traits ◽  
General Linear Model ◽  
Weaning Weight ◽  
Factors Affecting ◽  
Sex Effect ◽  
Beef Cattle Breeds

Growth traits of purebred calves of six beef breeds (Aberdeen Angus – AA, Blonde d’Aquitaine – BA, Charolais – CH,Hereford – HE, Limousine – LI and Beef Simmental – BS) born from 1998 to 2002 were analysed. Traits under study were birth weight (BW), weight at 120 days (W120), weight at 210 days – weaning weight (WW), weight at 365 days – yearling weight (YW) and average daily gains from birth to 120 days (ADG1), from birth to 210 days (ADG2), from birth to 365 days (ADG3), from 120 to 210 days (ADG4). General linear model with class effects of breed, dam’s age at calving, sex, herd-year-season (HYS) and covariation of age at weighing was used for analyses. All effects significantly affected both weight and gain traits except for dam’s age that was significant for BW, W120, YW and ADG3, and age at weighing that was significant for W120, WW, YW, ADG2, ADG3, ADG4. Estimated least squares means of growth traits were compared using Scheffe’s multiple-range tests. Highest BW (40.57 kg) and W120 (172.43 kg) were found for BA calves. BS calves had highest WW (260.30 kg), YW (424.07 kg), ADG1 (1 154 g), ADG2 (1 053 g), ADG3 (1 054 g) and ADG4 (1 098 g). Highest BW, YW, ADG3 and ADG4 were found for males-singles. Males-twins had highest W120, WW, ADG1 and ADG2. Calves descending from 5–7 years old dams had highest BW, W120, WW, ADG1, ADG2 and ADG4. The proportion of variability of growth traits explained by HYS effect (42.96–71.69%) was high, whereas proportions of variability explained by SEX effect (2.03–5.77%), age of dam (1.02–2.24%) and breed (1.05–2.21%) were low. Residuals accounted for 23.71 up to 53.79% of total variance.  

scholarly journals The Effect of Stress on Reproduction and Reproductive Technologies in Beef Cattle—A Review

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2096 ◽  
Author(s):  
Aitor Fernandez-Novo ◽  
Sonia S. Pérez-Garnelo ◽  
Arantxa Villagrá ◽  
Natividad Pérez-Villalobos ◽  
Susana Astiz
Keyword(s):  
Beef Cattle ◽  
Reproductive Performance ◽  
Stress Responses ◽  
Production Systems ◽  
Reproductive Technologies ◽  
Neural Systems ◽  
Factors Affecting ◽  
Health And Nutrition ◽  
Beef Herds ◽  
Major Factors

Researchers have contributed by increasing our understanding of the factors affecting reproduction in beef, mainly physical health and nutrition aspects, which have been main concerns during decades. Animal welfare is of outmost relevance in all animal production systems and it is strongly associated to stress. Stress responses involve endocrine, paracrine and neural systems and the consequences of this stress on the reproductive efficiency of specifically, beef cattle and bulls, need to be highlighted. We, therefore, describe the fundamentals of stress and its quantification, focusing in beef herds, reviewing the highly valuable pieces of research, already implemented in this field. We examine major factors (stressors) contributing to stress in beef cattle and their effects on the animals, their reproductive performance and the success of reproductive biotechnologies. We include terms such as acclimatization, acclimation or temperament, very relevant in beef systems. We examine specifically the management stress due to handling, social environment and hierarchy or weaning effects; nutritional stress; and thermal stress (not only heat stress) and also review the influence of these stressors on reproductive performance and effectiveness of reproductive biotechnologies in beef herds. A final message on the attention that should be devoted to these factors is highlighted.

Bio-economic evaluation of grazing-management options for beef cattle enterprises during drought episodes in semiarid grasslands of northern Australia

2021 ◽  
Vol 61 (1) ◽  
pp. 72
Author(s):  
M. K. Bowen ◽  
F. Chudleigh ◽  
D. Phelps
Keyword(s):  
Beef Cattle ◽  
Management Strategies ◽  
Grazing Management ◽  
Economic Modelling ◽  
Stocking Rate ◽  
Northern Australia ◽  
Management Scenarios ◽  
Management Options ◽  
Herd Management ◽  
Stocking Rates

Context The large inter-annual and decadal rainfall variability that occurs in northern Australian rangelands poses major challenges for the profitable and sustainable management of grazing businesses. Aims An integrated bio-economic modelling framework (GRASP integrated with Breedcow and Dynama (BCD)) was developed to assess the effect of alternative grazing-management options on the profitability and sustainability of a beef cattle enterprise in the central-western Mitchell grasslands of Queensland over a multi-decadal time period. Methods Four grazing-management strategies were simulated over a 36-year period (1982–2017) in the GRASP pasture-growth model, using historic climate records for Longreach in central-western Queensland. Simulated annual stocking rates and steer liveweight-gain predictions from GRASP were integrated with published functions for mortality and conception rates in beef-breeding cattle in northern Australia, and then used to develop dynamic BCD cattle-herd models and discounted cash-flow budgets over the last 30 years of the period (1988–2017), following a 6-year model-equilibration period. The grazing-management strategies differed in the extent to which stocking rates were adjusted each year, from a common starting point in Year 1, in response to changes in the amount of forage available at the end of the summer growing season (May). They ranged from a low flexibility of ‘Safe stocking rate’ (SSR) and ‘Retain core herd’ (RCH) strategies, to a moderate flexibility of ‘Drought responsive’ (DR), to a ‘Fully flexible’ (FF) strategy. The RCH strategy included the following two herd-management scenarios: (1) ‘Retain herd structure’, where a mix of cattle were sold in response to low pasture availability, and (2) ‘Retain core breeders’, where steers were sold before reducing the breeder herd. Herd-management scenarios within the DR and FF strategies examined five and four options respectively, to rebuild cattle numbers and utilise available pasture following herd reductions made in response to drought. Key results Property-level investment returns expressed as the internal rate of return (IRR) were poor for SSR (–0.09%) and the three other strategies when the herd was rebuilt following drought through natural increase alone (RCH, –0.27%; DR, –1.57%; and FF, –4.44%). However, positive IRR were achieved when the DR herd was rebuilt through purchasing a mix of cattle (1.70%), purchasing pregnant cows (1.45%), trading steers (0.50%) or accepting cattle on agistment (0.19%). A positive IRR of 0.70% was also achieved for the FF property when purchasing a mix of cattle to rebuild numbers. However, negative returns were obtained when either trading steers (–2.60%) or agistment (–0.11%) scenarios were applied to the FF property. Strategies that were either inflexible or highly flexible increased the risk of financial losses and business failure. Property-level pasture condition (expressed as the percentage of perennial grasses; %P) was initially 69%P and was maintained under the DR strategy (68%P; average of final 5 years). The SSR strategy increased pasture condition by 25% to 86%P, while the RCH and FF strategies decreased pasture condition by 29% (49%P) and 65% (24%P) respectively. Conclusions In a highly variable and unpredictable climate, managing stocking rates with a moderate degree of flexibility in response to pasture availability (DR) was the most profitable approach and also maintained pasture condition. However, it was essential to economic viability that the property was re-stocked as soon as possible, in line with pasture availability, once good seasonal conditions returned. Implications This bio-economic modelling analysis refines current grazing-management recommendations by providing insights into both the economic and sustainability consequences of stocking-rate flexibility in response to fluctuating pasture supply. Caution should be exercised in recommending either overly conservative safe stocking strategies that are inflexible, or overly flexible stocking strategies, due to the increased risk of very poor outcomes.

scholarly journals The potential for modification in cloning and vitrification technology to enhance genetic progress in beef cattle in Northern Australia

2014 ◽  
Vol 148 (3-4) ◽  
pp. 91-96 ◽  
Author(s):  
Andrew W. Taylor-Robinson ◽  
Simon Walton ◽  
David L. Swain ◽  
Kerry B. Walsh ◽  
Gábor Vajta
Keyword(s):  
Beef Cattle ◽  
Northern Australia ◽  
Genetic Progress

Prediction of methane emissions from beef cattle in tropical production systems

1999 ◽  
Vol 50 (8) ◽  
pp. 1335 ◽  
Author(s):  
G. J. McCrabb ◽  
R. A. Hunter
Keyword(s):  
Beef Cattle ◽  
Greenhouse Gas ◽  
Production Systems ◽  
Methane Emissions ◽  
Northern Australia ◽  
Greenhouse Gas Inventory ◽  
Intergovernmental Panel ◽  
Respiration Chamber ◽  
The United Kingdom ◽  
Tropical Forage

The northern beef cattle herd accounts for more than half of Australia’s beef cattle population, and is a major source of anthropogenic methane emissions for Australia. National Greenhouse Gas Inventory predictions of methane output from Australian beef cattle are based on a predictive equation developed for British breeds of sheep and cattle offered temperate forage-based diets. However, tropical forage diets offered to cattle in northern Australia differ markedly from temperate forage-based diets used in the United Kingdom to develop the predictive equations. In this paper we review recent respiration chamber measurements of daily methane production for Brahman cattle offered a tropical forage or high grain diet, and compare them with values predicted using methodologies of the Australian National Greenhouse Gas Inventory Committee and the Intergovernmental Panel on Climate Change. We conclude that a reliable inventory of methane emissions for cattle in northern Australia can only be achieved after a wider range of tropical forage species has been investigated. Some opportunities for reducing methane emissions of beef cattle by dietary manipulation are discussed.

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