Merino research gains weight

Breeding Merino sheep that can withstand harsh summers across southern Australia without losing weight is a step closer to reality.

Such sheep could potentially reduce feed costs and the risks of running livestock in areas of high seasonal variability and boost ewe reproductive performance and lamb production.

Sheep Cooperative Research Centre (Sheep CRC) post-graduate student Gus Rose has found that Merino ewes can be bred to lose less weight in summer when there is poor feed and gain more weight during the spring flush.

"This is a step towards breeding sheep that are better adapted to Australian pasture conditions and that will be more tolerant of climate variations in the longer term," he said.

Mr Rose's four-year PhD project is investigating the genetic and economic value of sheep resilience to liveweight loss in summer and autumn.

He is being supervised by a team of Sheep CRC researchers in Perth and Armidale, New South Wales.

Mr Rose said the problem of sheep weight loss during summer affected most livestock enterprises in Mediterranean environments in Australia and overseas.

He said reducing weight loss without incurring high feed costs, especially for breeding ewes, would be a major plus for livestock producers around the globe.

"It would also reduce the risks and costs of maintaining sheep in good condition during summer in more marginal areas with inconsistent rainfall," he said.

"There may also be potential to run more sheep than normal in these areas and increase returns."

Mr Rose is also working in collaboration with the Netherlands-based Animal Breeding and Genomics Centre at Wageningen University, where researchers are assessing the genetic robustness and fitness of cows.

"The Dutch have developed a good scientific knowledge about animal adaptation and it is a good fit for my research," he said.

Mr Rose analysed five years of data from a sheep resource flock in Katanning to discover the heritability of variations in Merino weight loss and gain.

His findings were recently presented to the annual European Federation of Animal Science (EAAP) convention, where he won the prestigious prize for best scientific poster in the genetics category from a field of 100 participants.

Stage two of Mr Rose's PhD project will investigate the genetic and economic links between sheep resilience to live weight changes and other important production traits, such as wool weight and reproductive performance.

He said that this process would include surveying farmers across Australia to identify the main profit-driving traits for Merino enterprises in a wide range of geographic environments.

"Once we know that sheep can be genetically robust and resistant to summer weight loss during times of low feed availability, then we can start to work out the best breeding objectives to target other economically important traits in these flocks," he said.