The effect of SCD and FASN gene polymorphisms on milk fatty acid composition in Holstein breed

This study examined the genotype distribution of the SCD and FASN gene loci and their association with milk fatty acid composition in Holstein cows. The SCD and FASN gene loci genotype distribution was found in Hardy-Weinberg Equilibrium. The SCD gene locus showed a genotype distribution of TT, TC, and CC with frequencies of 0.21, 0.44, and 0.35, respectively. Meanwhile, T and C allele frequencies were 0.43 and 0.57, respectively. For the FASN gene locus, the frequencies of genotypes AA, AG, and GG were 0.15, 0.35, and 0.50, respectively, with allele frequencies of 0.33 for A and 0.67 for G. Significant relationships were observed between the SCD gene polymorphism and the fatty acids C4:0, C11:0, C18:1 trans6, C18:3n3, and C20:2, with the highest averages recorded in the TT and TC genotypes. The FASN gene polymorphism was associated with SFA, MUFA, and PUFA, notably C14:0, C18:1 trans9, C18 trans11, C24:1 n9, C18:2n6, C18:3n3, and C22:6 n3, with prominent prevalence in the AA, GG, and AG genotypes. These findings underscore the potential significance of these gene polymorphisms in influencing fatty acid profiles, and they might be potential markers for modifying fatty acid composition.