Genomic analysis of dominance effects in milk production and conformation traits of Fleckvieh cattle

Abstract

Dominance is the phenomenon of intra-locus interaction of alleles. Dominance variance in dairy cattle estimated from pedigree data shows a large variation and amounts to up to 50% of the genetic variance in conformation traits and 43% in milk production traits. With SNP genotypes of cows, dominance variance can be estimated both on the marker level and on the animal level using genomic dominance relationship matrices. Variance components of nine milk production and conformation traits were estimated in additive and dominance models by REML estimation and Gibbs sampling. Estimated dominance variance amounted to between 3.3% and 50.5% of the total genetic variance. REML and Gibbs sampling estimates showed good concordance. Although standard errors of dominance variance were rather large, dominance variance in milk, fat, protein yield, somatic cell score and milkability was significant.