Feed intake and efficiency in beef cattle: overview of recent Australian research and challenges for the future

In the last 10 years, there have been 3 major research and development projects in Australia on the efficiency of feed utilisation by beef cattle. The primary objective of these projects has been to examine individual animal variation in feed efficiency and its exploitation for genetic improvement in beef cattle. The results of these projects indicate that genetic variation in feed efficiency exists in Australian beef herds, that feed efficiency is moderately heritable and that the potential exists to reduce the cost of beef production through selection for efficient cattle. These results have been further developed for industry application through the generation of BREEDPLAN estimated breeding values for net ( or residual) feed intake ( a feed efficiency trait) for Angus and Hereford-Polled Hereford breeds. Although economic analyses have indicated substantial benefit from selection for feed efficiency, the high initial cost of identifying animals which are superior for feed efficiency is a barrier to rapid adoption of the technology. Developing cost-effective methods of implementing the feed efficiency technology is thus an on-going research activity. Challenges for the future include: the development and use of more sophisticated statistical analyses procedures ( such as random regression) for feed intake and efficiency evaluation; development of accurate methods of assessing individual animal feed intake at pasture; the adoption of a whole-production system approach to feed utilisation; and better integration of the disciplines of genetics and nutrition. The outcomes from research in the efficiency of feed utilisation in beef cattle have wider applications, not only in other livestock species, but also in human energetics, such as the control of obesity.