Quantitative trait loci detection and benefits from marker-assisted selection in dairy cattle

Summary

The first objective of this study was to map quantitative trait loci (QTL)affecting economically important traits: milk production traits, health traits and fertility traits in the Finnish Ayshire population. The second objective was to investigate the effects of using QTL information in marker-assisted selection (MAS) on the genetic response and the linkage disequilibrium between the different parts of the genome.
In conclusion, several QTL affecting economically important traits of dairy cattle were detected. Futher studies are needed to verify these QTL, check their presence in the present breeding population, look for pleiotropy and fine map the most interesting QTL regions. The results of the simulation studies show that using MAS together with embryo transfer to pre-select young bulls within families is a useful approach to increase genetic merit of the AI-bulls compared to conventional selection.