Strategy for applying genome-wide selection in dairy cattle.
Animals can be genotyped for thousands of single nucleotide polymorphisms (SNPs) at one time, where the SNPs are located at roughly 1-cM intervals throughout the genome. For each contiguous pair of SNPs there are four possible haplotypes that could be inherited from the sire. The effects of each interval on a trait can be estimated for all intervals simultaneously in a model where interval effects are random factors. Given the estimated effects of each haplotype for every interval in the genome, and given an animal's genotype, a 'genomic' estimated breeding value is obtained by summing the estimated effects for that genotype. The accuracy of that estimator of breeding values is around 80%. Because the genomic estimated breeding values can be calculated at birth, and because it has a high accuracy, a strategy that utilizes these advantages was compared with a traditional progeny testing strategy under a typical Canadian-like dairy cattle situation. Costs of proving bulls were reduced by 92% and genetic change was increased by a factor of 2. Genome-wide selection may become a popular tool for genetic improvement in livestock.
Schaeffer
L R
LR
Department of Animal and Poultry Science, Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada. lrs@uoguelph.ca
D000818:Animals; D001947:Breeding / Q000191:economics / Q000379:methods*; D002417:Cattle / Q000235:genetics*; D003612:Dairying / Q000379:methods*; D005260:Female; D005819:Genetic Markers; D016678:Genome / Q000235:genetics*; D006239:Haplotypes; D008297:Male; D008957:Models, Genetic; D012641:Selection, Genetic
D005819:Genetic Markers