Sheep Genetics Australia: A national genetic evaluation system for Australian sheep

Sheep Genetics Australia (SGA) was established to deliver a nationally consistent across-flock genetic evaluation platform to the Australian sheep industry, generating information relevant for both meat and wool sheep. Historically, data in three separate databases were evaluated by different organisations with different models, different bases and for different objectives. In addition, the results of these genetic evaluations were often presented in varying ways to the end-users, both stud breeders and commercial wool growers. To achieve the aim of a single national genetic evaluation language for Australian sheep breeders (wool & meat), some significant changes were necessary and a number of new developments were required. Three years of research and development were required and resulted in the SGA analysis as it is currently applied. Some changes were superficial and did not impact on the ranking of animals, but others changed both animal and flock rankings. Independent of changes to models and parameters used for the analysis, the simple merging of Merino data to form the MERINOSELECT™ database had a significant impact. The affected particularly the estimated breeding values of link sires with progeny across the three databases, and the ranking of flocks. Industry response to the single, combined analysis for Merinos, and the improved analysis for other breeds, has been very positive. This paper describes SGA and the analysis it uses to estimate Australian Sheep Breeding Values (ASBVs).