Proc. Assoc. Advmt. Anim. Breed. Genet. 17: 187-194 187 GENETIC EVALUATION FOR THE AUSTRALIAN SHEEP INDUSTRY D.J. Brown 1 , A.E. Huisman 1 , A.A. Swan 1 , H-U. Graser 1 , R.R. Woolaston 2 , A.J. Ball 3 , K.D. Atkins 4 and R.G. Banks 3 1 Animal Genetics and Breeding Unit ∗ , University of New England, Armidale, 2351, Australia 2 Pullenvale, Queensland, 4069, Australia 3 Meat and Livestock Australia, University of New England, Armidale, 2351, Australia 4 NSW Department of Primary Industries, Orange Agricultural Institute, Orange, 2800, Australia SUMMARY Sheep Genetics Australia (SGA) was established to deliver a national across-flock genetic evaluation system to the Australian sheep industry for terminal sires, maternal sires and Merinos. To achieve the aim of providing a single national genetic evaluation language for Australian sheep breeders, significant developments to existing systems were necessary and required various new innovations. These included the amalgamation of databases, data transformations, refinement of analysis models, genetic grouping methodology, updated genetic parameters, multiple trait across-flock linkage assessments, index development, and reporting changes. Since the establishment of SGA, research and development to further improve the system has continued. This paper describes SGA and the analysis used to estimate Australian Sheep Breeding Values (ASBVs). More information is located at www.sheepgenetics.org.au. INTRODUCTION Sheep Genetics Australia (SGA) was established in 2005 to deliver a nationally consistent across- flock genetic evaluation platform to the Australian sheep industry, generating information relevant for terminal, maternal and Merino sheep. SGA is a joint program of Australian Wool Innovations (AWI) and Meat and Livestock Australia (MLA). Historically, data in separate databases were evaluated by different organisations with different models, different genetic base points, and for different objectives. In addition, the results of these genetic evaluations were often presented in varying forms to the end-users, both ram breeders and commercial sheep producers. To achieve the aim of a single national genetic evaluation language, significant developments were necessary and a number of new innovations have been delivered to the Australian sheep industry. Three years of research and development were required to produce the first SGA analysis. Since then research and development has been continual and has resulted in the SGA analysis as it is currently applied. Some of the early 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 major impact. This affected particularly the estimated breeding values of link sires with progeny across the various 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. Since the release of the first SGA analysis in November 2005 the membership of all three databases ∗ AGBU is a joint venture of NSW Department of Primary Industries and the University of New England