Genomic selection can be used to balance improvement of lean meat yield and eating quality in terminal sire sheep breeds

Abstract

Terminal sire sheep breeders in Australia have made substantial genetic progress over more than 20 years, driven largely by the use of a selection index (Carcass Plus) which focuses improvement on growth and lean meat yield (lmy). Due to unfavourable genetic correlations, consumer eating quality of sheep meat has declined. Major advances in genetic evaluation have been made since 2016, with the introduction of 'single-step' genomic analyses (SS-GBLUP) to compute Australian Sheep Breeding Values (ASBVs) for all traits including carcass and eating quality (Brown et al. 2018), and a new index (EQ) which balances improvement in lean meat yield and eating quality (Swan et al. 2015). This evaluation system is underpinned by a genomic reference population where progeny of industry sires are genotyped and phenotyped for an extensive range of traits. A subset of the reference population were used in consumer eating quality trials, and have data on sensory scores which can be used to identify consumer preferences (Pannier et al. 2014).