Background
Our previous genome-wide association study (GWAS) in Chinese Holstein population revealed Glycosylphosphatidylinositol-anchored HDL binding protein1 (GPIHBP1) is a potential candidate functional gene for milk production traits [1]. A SNP which is located 1,295 bp upstream from the translation initiation site of GPIHBP1 gene showed strong association with milk yield trait, protein yield and fat percentage with P values 1.02E-10, 1.55E-07 and 6.30E-20, respectively. To confirm the association between the GPIHBP1 gene and milk production traits, we selected a SNP within 5′UTR of GPIHBP1 in another Chinese Holstein population for further association study. This SNP also showed very significant association with milk yield trait, fat percent trait and protein yield trait (unpublished data). Therefore, GPIHBP1