Single-Step Genetic Evaluations in the Australian Sheep Industry

The main benefit of genomic selection for Australian sheep is to increase the accuracy of estimates of genetic merit for hard to measure traits including carcass, adult wool and reproduction traits. An extensive genotyped reference population, combined with a significant number of genotyped and phenotyped animals from ram breeding flocks enables genomic predictions with improved accuracies. Genomically enhanced breeding values have now been transitioned from a mixture of blending and independent single-trait single-step methods into full multiple-trait single-step analyses covering most traits evaluated. Key challenges to achieve this were: weighting of pedigree and genomic information, achieving acceptable run times, and estimation of breeding value accuracy from genomic contributions. The new analyses have been shown to significantly improve the prediction of progeny performance across most traits. Future developments will evaluate alternate models for incorporating genomic information, ability to include genotyped animals without any pedigree and phenotypic information, and development of single-step analyses for reproduction traits.