Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 3, 1999
Publication Date: N/A
Interpretive Summary: The objective of this study was to identify DNA markers that could be used in the selection of bulls, with our long-term goal being to identify chromosomal regions important for milk production, health, and type traits in the US commercial Holstein population. Detection of genetic markers located near important genes controlling these traits might be rewarding to obreeders and also to researchers for use in marker-assisted selection. Thirty-four DNA markers located on 22 chromosomes were studied in seven large US Holstein families. Variations with some of these DNA markers were associated with significant effects for milk production traits and type traits in several families. Selection on these markers may increa genetic gain within these families and increase profits and sustainability for the US artificial insemination industry.
Quantitative trait loci affecting milk yield, health, and type traits were studied for seven large US Holstein grandsire families using the granddaughter design. The families were genotyped at 34 microsatellite markers on 22 chromosomes, and the effects of the marker alleles were analyzed for 28 traits (21 type traits, 5 milk traits, somatic cell score, and productive herd life). Six putative quantitative trait loci were identified within specific families; 3 affecting type traits on chromosomes 4, 5, and 17 and 3 affecting milk production traits on chromosomes 6, 26, and 29. This is the first report of 5 of these quantitative trait loci with continued support of a locus affecting protein percentage on chromosome 6.