Impact of ewe genotype on sire breeding values in genetic evaluation of Merino visual traits

Abstract

Merino ram breeders often place significant emphasis on visually assessed fleece traits within their breeding programs. There are concerns among Merino breeders that anecdotally Australian Sheep Breeding Values (ASBVs) of sires do not a lwa ys predict performance when sires are used in a different genetic background, or in other words, when joined to different ewe genotypes (often referred to as 'bloodlines'). Egerton-Warburton <i>et al</i>. (2019) reported that sire rankings for fleece traits were consistent across ewe genotypes, and that sire x ewe genotype interactions accounted for less than 2% of phenotypic variation.