DNA test 'accurate, affordable'

Flock-scale use of DNA testing is now within reach of Australia's sheep producers, with a new 12k SNP test available, delivering high levels of accuracy in predicting breeding values at half the cost of previous testing systems.

For the first time there will be no restriction on the number of tests any breeder can order, marking the start of a new era in sheep genetic improvement where the use of DNA testing is anticipated to play an increasingly important role.

The 12k tests have been developed by the Co-operative Research Centre for Sheep Industry Innovation (Sheep CRC) and are available from Sheep Genetics.

Sheep CRC chief executive James Rowe said the challenge in designing the test was to optimise the number and selection of gene markers to achieve the best possible accuracy while keeping costs low.

"The accuracy of predicting genomic breeding values, using the new 12k test, almost match that of the benchmark 50k test - and at less than half the cost," he said.

"At a price of just $50 a test, and based on the overwhelming demand for DNA tests during our pilot projects, we expect there will be very strong interest from producers keen to adopt this technology in order improve rates of genetic gain and the flexibility of their breeding objectives."

DNA testing allows sheep breeders to identify breeding stock which carry genes for favourable traits for production as well as for product quality, such as shearforce as a measurement of meat tenderness.

The predictions based on DNA analysis are used in conjunction with conventional measurement of performance and pedigree to produce Australian Sheep Breeding Values that can forecast which rams and ewes will breed the most productive lambs, thereby accelerating the rate of improvement in their flock.

Until now, the ovine 50k SNP chip, developed by the International Consortium for Sheep Genomics, has been used by the Sheep CRC for all genotyping research in the Information Nucleus Program and in the three genomic pilot projects conducted between 2010 and 2013.

While the price of the 50k SNP test has fallen during the past five years, it is still too expensive to form the basis of commercial genotyping in the sheep industry.

However, the results of a low-density SNP test like the 12k can be converted through a process of imputation to predict results equivalent to those obtained from 50k SNP testing.

Based on the experience of the beef and dairy industries and from the research results from the Information Nucleus Program, the Sheep CRC's genomics research team, led by Julius van der Werf and Ben Hayes, developed the new SNP panel specifically for the Australian sheep industry.

Professor Rowe said the "sweet spot" the research team found was the 12k SNP test.

For more information visit www.sheepgenetics.com.au .