Abstract

Whole genome single nucleotide polymorphism marker (SNP) technologies are rapidly being developed and could well play a role in the future selection of farmed animals. In sheep, work is being carried out to identify SNP`s associated with economically important production traits and disease resistance. Stud sheep breeders routinely cull up to 30% of lambs born due to a variety of faults. Despite this culling pressure, the faults keep occurring, suggesting low heritability, recessive inheritance or incomplete penetration of fault causing genes. The objective of this paper was to identify the potential of SNP fault detection and elimination in sheep. Simulation was used to predict changes in gene frequencies and in an index of genetic merit of production traits over time when between two and 30 SNPs were used to aid selection. The SNPs are assumed to predict the presence of deleterious recessive genes. As selection pressure applied to individual or combination SNPs increased, the rate of increase in production trait genetic merit slowed down. Thus, a balance would be required between the emphasis on SNPs actively used to select against genetic faults, relative to emphasis on genetic merit. This work identified scope for substantial economic benefits from application of SNP technology for removal of faults to both stud breeders and commercial sheep farmers.

JA, Sise, B Auvray, KG Dodds, and PR Amer

Proceedings of the New Zealand Society of Animal Production, Volume 68, Brisbane, Australia, 33-36, 2008