The aim of this study was to investigate the relationship between genes that encode fatty acid-binding protein 4 (FABP4), nuclear receptor subfamily 1, group H, member 3, (NR1H3) and stearoyl-CoA desaturase (SCD) proteins and some milk yield traits in Holstein cattle. A total of 166 Holstein dairy cows were used for the study. Genotyping was performed by polymerase chain reaction and restriction length polymorphism (PCR-RFLP) method. The frequencies of FABP4-G (82%), NR1H3-G (96%) and SCD-C (73%) alleles were found to be high in the examined Holstein cows. According to chi-square test results, the investigated Holstein cows were in Hardy-Weinberg (HW) equilibrium for the FABP4 and SCD genes while significant deviation was observed from HW equilibrium for the NR1H3 gene.
Regression analyses revealed that NR1H3 genotypes were associated with milk fat (P<0.05), SCD genotypes were
associated with dry matter without fat (P<0.05) and FABP4 genotypes were associated with milk density (P<0.01).
Taken together, our results indicate that investigated SNPs may be used in the selection programs related with the milk
composition traits in dairy cattle.