The influence of milk protein phenotypes on fatty acid composition of milk from Holstein cows

To compare the milk fatty acid composition of cows with different milk protein phenotypes, 592 milk samples from 233 Holstein cows were analyzed for kappa-casein and beta-lactoglobulin phenotypes and for fatty acid composition. Milk fat from cows with kappa-casein BB had the highest concentrations of 12:0 and lowest concentrations of 18:0, and milk fat of cows with kappa-casein AB had the lowest concentrations of 16:0. The B variant of P-lactoglobulin was associated linearly with greater concentrations of 14:0, 16:0, and 16:1 and lower concentrations of 18:0 and 18:1 in milk fat in comparison to the A allele. The results suggest that the B variants of kappa-casein and beta-lactoglobulin are associated with higher concentrations of de novo synthesized fatty acids at the expense of 18:0 in milk fat, which has implications on texture and sensory properties of dairy products. Therefore, genetic selection for the B variants of kappa-casein and beta-lactoglobulin could be used as an aid to manufacture dairy products with more desirable characteristics.