title: Estimation of genetic parameters and detection of quantitative trait loci for metabolites in Danish Holstein milk.
abstract: Small components and metabolites in milk are significant for the utilization of milk, not only in dairy food production but also as disease predictors in dairy cattle. This study focused on estimation of genetic parameters and detection of quantitative trait loci for metabolites in bovine milk. For this purpose, milk samples were collected in mid lactation from 371 Danish Holstein cows in first to third parity. A total of 31 metabolites were detected and identified in bovine milk by using (1)H nuclear magnetic resonance (NMR) spectroscopy. Cows were genotyped using a bovine high-density single nucleotide polymorphism (SNP) chip. Based on the SNP data, a genomic relationship matrix was calculated and used as a random factor in a model together with 2 fixed factors (herd and lactation stage) to estimate the heritability and breeding value for individual metabolites in the milk. Heritability was in the range of 0 for lactic acid to >0.8 for orotic acid and β-hydroxybutyrate. A single SNP association analysis revealed 7 genome-wide significant quantitative trait loci [malonate: Bos taurus autosome (BTA)2 and BTA7; galactose-1-phosphate: BTA2; cis-aconitate: BTA11; urea: BTA12; carnitine: BTA25; and glycerophosphocholine: BTA25]. These results demonstrate that selection for metabolites in bovine milk may be possible.
authors.affiliation: Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, PO Box 50, DK-8830 Tjele, Denmark. bart.buitenhuis@agrsci.dk
authors.forename: A J
authors.initials: AJ
authors.lastname: Buitenhuis
authors.forename: U K
authors.initials: UK
authors.lastname: Sundekilde
authors.forename: N A
authors.initials: NA
authors.lastname: Poulsen
authors.forename: H C
authors.initials: HC
authors.lastname: Bertram
authors.forename: L B
authors.initials: LB
authors.lastname: Larsen
authors.forename: P
authors.initials: P
authors.lastname: Sørensen
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D005260:Female; D060005:Genotyping Techniques / Q000662:veterinary; D007774:Lactation / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D008892:Milk / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000662:veterinary; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*