Understanding Genomics

Photo: SNP (Source: David Hall)

Genomics is the knowledge of the genes and chromosomes and how they affect characteristics of an individual. It is already allowing our sheep researchers to predict the later performance of sheep from an early age — even just after birth.

In sheep, genomics is mainly used to study the relationship between performance of important traits and known points on the sheep’s chromosomes, known as SNPs (pronounced ‘snips’).

The measured performance of a trait in many individual sheep is compared with a large number of SNPs in those same individuals. The pattern that emerges shows which SNPs are related to the trait and how strong an effect the presence of each SNP has on the characteristic.

Once sufficient tests are completed, these form the basis of a DNA test that can be used commercially to predict trait performance in other individual sheep. The DNA test results will be reported through Sheep Genetics in the form of enhanced Australian Sheep Breeding Values. Gnomically enhanced breeding values offer new opportunities for early selection decisions with young sires to achieve genetic improvement across a range of traits including new traits that breeders are unable to measure on-farm, such as intramuscular fat and shear force or tenderness, or take a long time to measure, such as adult fleece weight and fibre diameter.
The Sheep CRC and Sheep Genetics, have already completed an initial round of comparisons (Genomics Pilot Project I) to create research breeding values (RBVs) based on genomic data for some 360 young industry sires from 200 breeders for a number of important performance traits.

A second pilot (Genomics Pilot Project II) involving 1,000 young sires is underway to further develop commercial SNP tests and the inclusion of their results into Australian Sheep Breeding Values (ASBVs).

Commercially available SNP tests from this work are likely to be available for sheep during 2012.

Click here to go to 'Genomics - Frequently asked questions'.
 

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