Animal Production Science
Volume 58 Number 8 2018
Animal Production 2018: Fostering Innovation through the Value Chain
AN17897Key determinants of pig welfare: implications of animal management and housing design on livestock welfare
Public concerns and policy debates about animal welfare often focus on intensive housing systems for farm animals. The most important determinants of farm animal welfare are not specific to any one type of housing system. Irrespective of the housing system, the design and management of the housing system are a major determinant of animal welfare.
AN17776Developing a heat load index for lactating dairy cows
Heat stress is a significant issue for the dairy industry worldwide. Traditionally the THI has been used as an indicator of intensity of heat load. However the THI does not incorporate wind speed or solar radiation. Therefore the THI may be under predicting the severity of heat load. Here describes a new heat load index for Australian dairy cattle.
AN17773Maintaining the appeal of Australian lamb to the modern consumer
Consumption of lamb has declined in Australia over recent decades as it is often considered too time consuming to cook and too fatty. To address this decline, the lamb industry has created a number of new cuts, investigated consumers’ preferences for roasts and provided nutritional information to market new lamb cuts. Continued development of products that suit the constantly changing consumers are required to keep lamb competitive in the market place.
AN17797Forage management and concentrate supplementation effects on performance of beef calves
Supplementation of beef calves may be a profitable management practice, but it is usually overlooked because the calves benefit from the cow’s milk production. However, supplementing beef calves with concentrate may increase performance and decrease some potential nutritional limitations during their first 6–7 months after birth. In addition to increased performance, early supplementation may cause some physiological changes that will enhance productivity later in the calf’s life. In spite of the observed benefits, supplementation of beef calves needs to be conducted with criteria to achieve favourable economic return.
AN17725Heat stress: impact on livestock well-being and productivity and mitigation strategies to alleviate the negative effects
Heat stress is a multifaceted issue that negatively impacts the welfare and productivity of livestock worldwide. It reduces the production of animal products for human consumption and increases rates of morbidity and mortality in livestock. Therefore, improving on and developing effective mitigation strategies that either prevent heat stress or assist in recovery following exposure to high ambient temperatures is essential to maintain appropriate animal welfare standards and increase production efficiency.
AN17779Variation in residual feed intake depends on feed on offer
This paper provides and reviews evidence that when energy supply is limited there is minimal variation between animals in residual feed intake. This suggests that the primary source of variation in residual feed intake must be in appetite rather than efficiency.
AN17772Benefits and costs of grazing various proportions of perennial ryegrass and chicory for dairy production
Understanding the trade-off between the cost of pasture renovation and seasonal requirements for supplementary feed is important when considering investment in alternative forages. A rainfed dairy farm was used to show that sowing a proportion of the milking area to chicory was equally or more profitable than perennial ryegrass alone over a 15-year period. For an individual farm, the most profitable percentage will fluctuate over time depending on prices, seasonal conditions and management choices.
Palates link soil and plants with herbivores and humans through three processes: flavour–feedback relationships at a cellular level; availability of nutrient-rich foods; and cultures that know how to combine wholesome foods into meals that nourish and satiate. Health ensues when these processes and linkages are intact; illness ensues when any of these links is broken. This paper describes ways to mend broken linkages.
AN17761Practical implications of mineral and vitamin imbalance in grazing sheep
Rapid progress in research on mineral functions in biology has provided new and unexplored implications for health and production in grazing livestock. This review describes the risks of imbalanced mineral and vitamin intakes in sheep grazing pastures and vegetative crops with a focus on different productive and environmental stresses. Balancing mineral and vitamin intake through increased nutritional diversity may require a redesign of grazing systems.
AN17780Grazing pressure, land condition, productivity and profitability of beef cattle grazing buffel grass pastures in the subtropics of Australia: a modelling approach
Queensland graziers often use higher stocking rates for perennial pastures than recommended by science organisations. The present study suggests that high stocking rates on buffel grass pastures are likely to have substantial financial and economic benefits over the medium term, even if land condition and animal productivity are declining and despite potential adverse consequences for long-term sustainability. Further research is needed to understand the effects of high utilisation rates of sown pastures on land condition and economic outcomes.
AN17770Sheep residual feed intake and feeding behaviour: are ‘nibblers’ or ‘binge eaters’ more efficient?
Is sheep feeding behaviour related to their feed conversion efficiency? This paper explores the relationship between number of meals, meal size and eating rate measured using automated feeders and feed conversion efficiency expressed as residual feed intake (RFI). Decreased daily meal number was associated with increased efficiency (lower RFI) in ewes. Changes in feeding behaviour may influence the management of sheep with improved feed conversion efficiency.
AN17781Using temporal associations to determine postpartum oestrus in tropical beef cows
Monitoring social and sexual behaviour in groups of cattle can provide a means of predicting and measuring individual reproductive performance by helping identify key reproductive events. The present study investigated the use of time-sequence data of cows and bulls accessing a watering point and found that the data had the potential to determine postpartum anoestrus periods. Development of the technology could assist early culling decisions and enhance genetic improvement of reproductive efficiency.
AN17794Cumulative reproductive performance effect on overall lifetime productivity in Merino sheep
Higher reproduction leads to higher selection intensities for current lifetime production and a greater potential rate of genetic gain. Recent research has shown benefit of keeping partial age groups of selected older ewes for longer, but little research has been done on cumulative effects of reproductive performance on later productivity, reproduction and health. The results showed that age has a bigger effect on productivity and dental health than does cumulative lifetime reproduction; and genetics and environment determine the level of impact with age.
AN17782The influence of the level of ewe gestation nutrition and lamb finishing diet on long-chain polyunsaturated fat concentration, antioxidant and mineral status, and colour stability of meat
The evaluation of nutritional constraints placed on ewes and their progeny is important for understanding their economic impact on sheep meat production systems. This study examined the effects of ewe gestation nutrition (EGN) and lamb finishing diet (LFD) on essential fatty acid (EFA), vitamin E, mineral content and colour stability of meat in wether lamb progeny. ENG provided at CS3.0 altered EFA concentrations, while CS2.5 reduced redness of meat at retail display when compared with their counterparts; however, LFD significantly affected EFA and vitamin E concentration, but not the iron content of meat.
AN17795Preliminary estimation of fat depth in the lamb short loin using a hyperspectral camera
Accurate carcass yield measurements provide many potential benefits to the red meat value chain in improving compliance to market specifications. The present study assesses the possibility of using a near-infrared hyperspectral camera to classify carcass surface regions as subcutaneous fat or muscle, and estimate fat depths of up to 12 mm. The techniques developed in the present study will be used to estimate fat coverage to predict total fat, and, subsequently, lean meat yield in the carcass.
AN17807Data capture through Australian beef cattle and meat sheep value chains: opportunities for enhanced feedback to commercial producers
Data capture at different points of livestock value chains is increasing rapidly, and there are opportunities for better use of this data. This paper provides an overview of what is currently being captured and shared along the Australian red meat value chains, and provides practical principles for effective feedback systems. While permissions add a complication to information sharing across the chain, benefits can be gained by the entire industry.
AN17777A mathematical model to predict the risk arising from the pasture infectivity of four nematode species in Australia
Gastrointestinal parasites cost the Australian sheep industry AU$436 million annually. Early warning of impending worm risk may reduce this cost by providing producers with sufficient time to implement control strategies. A predictive model of the risk arising from nematode pasture infectivity was developed and incorporated into the Sheep CRC’s ‘ASKBILL’ application (www.askbill.com.au).
AN17766Calcium and magnesium status of pregnant ewes grazing southern Australian pastures
Imbalances of macro-minerals are associated with ewe and lamb losses; however, the effect of subclinical imbalances is unknown. Ca and Mg status of ewes in late pregnancy was assessed to evaluate the risk of subclinical mineral disorders in ewes grazing typical southern Australian pastures. Mineral concentrations in pre-lambing blood and urine samples indicate that there is a risk of subclinical hypocalcaemia and hypomagnesaemia.
AN17559Impact of sire on the lifetime susceptibility of their progeny to breech strike in a Mediterranean environment
Identifying the risk factors that make sheep susceptible to blowfly strike is important in order to breed indirectly for breech strike resistance. This study compares the progeny of highly resistant and highly susceptible sires for susceptibility to breech strike and for differences in visual traits over the ewes’ lifetime. The results confirm that wrinkles and dags are main indicators, but that the difference is smaller than anticipated, which indicates that other unknown factors contribute to breech strike susceptibility.
AN17769Evaluating the economics of short-term partial mixed ration feeding decisions for dairy cows
The economics of short-term partial mixed ration (PMR) feeding decisions were analysed where it was assumed the infrastructure to feed out a mixed ration was already available. Feeding PMR plus canola meal under restricted pasture availability in early lactation resulted in higher milk production and contributed more to profit than did feeding grain in the dairy and forage in the paddock or PMR without canola meal. In late lactation, each diet made similar contributions to profit because of similar milk production.
AN17771Seed contamination in sheep: new investigations into an old problem
Seed contamination of sheep fleece and carcasses causes significant production losses. Recent studies have indicated that distribution and frequency of carcass damage across Australia are associated with the distribution of barley and brome grass populations, and varies with state, region, year, animal and climate factors. Reviewing the literature on this issue highlights areas requiring future research, including the investigation of effective weed-management strategies for current Australian conditions.
AN17813Ewe culling and retention strategies to increase reproductive rates in Merino sheep
Ewe culling and retention decisions can be based on litter size and rearing type of Merino ewes. Culling strategies based on twice dry or twice lambed and lost decrease the proportion of dry ewes in a flock. Lifetime reproductive performance is an efficient means of selecting a cohort of older ewes to retain in the flock.
AN17815Development of a system to rank perennial ryegrass cultivars according to their economic value to dairy farm businesses in south-eastern Australia
Perennial ryegrass is the main pasture species grown on dairy farms in south-eastern Australia, but with more than 60 commercially available cultivars, choosing the most suitable cultivar can present a challenge for farmers. This research aimed to develop an economically based framework providing comparative information on the agronomic performance and value of perennial ryegrass cultivars to farming systems. Australian dairy farmers can now make more informed decisions when purchasing perennial ryegrass seed.
AN17775The value of objective online measurement technology: Australian red meat processor perspective
The adoption of online measurement technologies for measuring carcass and meat-quality traits objectively has been low among Australian red meat processors. The aim of the present work was to obtain a greater understanding of Australian processor views on the value of objective online measurement technologies. Increased adoption of online measurement technologies has the potential to achieve benefits to the whole of industry.