Beta-Lactoglobulin content of bovine milk is affected by multiple mutations on BTA11

Abstract Text:

About 80% of the differences in β-lactoglobulin content of milk are due to genetic factors. Results from a GWAS showed that a region on BTA11 which contains the β-lactoglobulin gene has a major effect on β-lactoglobulin content. In this study we fine map this region using imputed 777k SNP data and we constructed haplotypes based on QTag-SNPs in order to capture the genetic variation associated with this region. We identified 4 haplotypes (A₁, A₂, B₁ and B₂) with significantly different effects on β-lactoglobulin content. This suggests that this region contains multiple mutations that affect milk β-lactoglobulin content. The difference in β-lactoglobulin content between the extreme haplotype groups A₁A₁ and B₁B₁ is 3.2%. The haplotypes explain 93% of the genetic variation in β-lactoglobulin content and therefore provide an efficient selection tool to reduce β-lactoglobulin content of milk and to increase cheese production.

Keywords:

dairy cattle

β-lactoglobulin

fine mapping

haplotypes