Sheep's genetic revolution nears

WITHIN two years, sheep breeders will be sending off blood samples to test for key genetic markers contained within individual animals.Being able to cull stud lambs at weaning that carry genes for poor worm resistance, staple strength, fertility or dark fibres will soon be a reality according to Meat and Livestock sheep genomics director, Dr Rob Forage.This is all possible because the genetic make-up of the sheep is now largely known, although exact genetic codes or DNA markers that code for very particular traits are still being explored. The sheep genome map is been put together with significant assistance from what is known of the human, cattle and dog genomes or genetic maps.So far, researchers have been able to piece the massive puzzle together to form the “virtual sheep genome”, and while the search for markers continues, Dr Forage said significant benefits from current knowledge is about to flow. “Over the next six to 12 months we will see big steps forward,” he said.“We are currently part of an international effort to find about 50,000 DNA sheep markers that will lead to high performance sheep breeding in the not too distant future.”Knowing how these genes interact is another challenge currently being tackled at the Faulkiner Research Station near Deniliquin, NSW.About 100 traits have been measured on more than 5000 animals and this information will be matched with the 50,000 markers to associate traits with markers and from this the researchers will be developing a diagnostic tool for producers to use and this is where the blood test will come in.“It will be a massive number crunching exercise to put this together, but it will lead to significant genetic gain for the sheep industry,” Dr Forage said.“It is a very exciting time.”The Faulkiner work is also establishing what is known as a haplotype map which will help researchers know how various sections of DNA interact with each other. More traditional stud breeders have often questioned the science and the massive resources being poured into genetics. For example the new Sheep Co-operative Research Centre will focus on genetics and is worth $110 million.While Dr Forage understands the concerns from breeders that new genetic tools will lead to unbalanced animals that are not suited to their environment, he says the genetic revolution is just delivering an aid for breeders.“The criticism comes from a sound point of view, but this is not about giving up your day job. “There is no substitute for taking the animal into account itself. This is simply about developing a state-of-the-art diagnostic tool for traits that are very hard to measure otherwise.”* Hear more of what Dr Forage has to say at www.stockandland.com