title: Association between milk protein gene variants and protein composition traits in dairy cattle.
abstract: The objective of this study was to identify DNA markers in the 4 casein genes (CSN1S1, CSN1S2, CSN2, and CSN3) and the 2 major whey protein genes (LALBA and LGB) that show associations with milk protein profile measured by reverse-phase HPLC. Fifty-three single nucleotide polymorphisms (SNP) were genotyped for cows in a unique resource population consisting of purebred Holstein and (Holstein × Jersey) × Holstein crossbred animals. Seven traits were analyzed, including concentrations of α(S)-casein (CN), β-CN, κ-CN, α-lactalbumin, β-lactoglobulin, and 2 additional secondary traits, the total concentration of the above 5 milk proteins and the α(S)-CN to β-CN ratio. A substantial fraction of phenotypic variation could be explained by the additive genetic component for the 7 milk protein composition traits studied. Moreover, several SNP were significantly associated with all examined traits at an experiment-wise error rate of 0.05, except for α-lactalbumin. Importantly, the significant SNP explained a large proportion of the phenotypic variation of milk protein composition. Our findings could be used for selecting animals that produce milk with desired composition or desired processing and manufacturing properties.
authors.affiliation: Department of Dairy Science, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: F
authors.initials: F
authors.lastname: Peñagaricano
authors.forename: K R
authors.initials: KR
authors.lastname: Ahmad
authors.forename: J A
authors.initials: JA
authors.lastname: Lucey
authors.forename: K A
authors.initials: KA
authors.lastname: Weigel
authors.forename: H
authors.initials: H
authors.lastname: Khatib
mesh_terms: D000818:Animals; D002364:Caseins / Q000235:genetics; D002417:Cattle / Q000235:genetics; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D056148:Chromatography, Reverse-Phase / Q000662:veterinary; D005260:Female; D056726:Genetic Association Studies / Q000662:veterinary; D005838:Genotype; D007768:Lactalbumin / Q000235:genetics; D007782:Lactoglobulins / Q000235:genetics; D015810:Linkage Disequilibrium / Q000235:genetics; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000032:analysis / Q000235:genetics*; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D000067816:Whey Proteins
chemical_list: D002364:Caseins; D007782:Lactoglobulins; D008894:Milk Proteins; D000067816:Whey Proteins; D007768:Lactalbumin