The effect of mutations in stearoyl CoA desaturase gene and fatty acid synthase on milk composition and fatty acid profile in milk fat of dairy cows

The effects of diet on milk fatty acid profile, including conjugated linoleic acid (CLA) have been well documented, however, there is limited information on the interaction of diet with genetics. The objective of this research was to determine the effect of single nucleotide polymorphisms (SNP) in the stearoyl CoA desaturase (SCD) gene on the ability to produce CLA in dairy cows fed low and high fat diets. The secondary objective was to determine the effect of a SNP in fatty acid synthase (FASN) on milk yield and composition. There was no effect of SCD genotype on CLA concentration, however there was an effect of SCD genotype on the ratio of C14:1/C14:0 which tended to be associated with CLA concentration when animals were fed a high fat diet. The FASN genotype affected milk yield, while composition remained constant.