Dietary marine algae (Schizochytrium sp.) increases concentrations of conjugated linoleic, docosahexaenoic and transvaccenic acids in milk of dairy cows

Modification of milk fat to contain long-chain (n-3) fatty acids and increa sed concentrations of conjugated linoleic acid has potential for improving health of consumers. Natural modification of milk through nutritional manip ulation of diets for dairy cows is preferable to post-harvest modification. The objectives of this study were to increase the concentrations of benefi cial fatty acids in milk fat by feeding a diet rich in (n-3) fatty acids fr om algae to dairy cows. Cows were fed a control diet, a diet containing alg ae (Schizochytrium sp.) protected against ruminal biohydrogenation, or a di et containing unprotected algae for 6 wk. Feed intake and milk production w ere recorded daily. Milk samples were obtained weekly for analysis of milk composition and profile of fatty acids. Percentage of fat in milk of cows f ed algae was lower (P < 0.01) than in milk from cows fed the control diet; however, energy-corrected milk production did not differ (P > 0.05), Inclus ion of algae in diets decreased (P < 0.01) feed intake. Milk fat from cows fed algae contained greater (P < 0.01) concentrations of conjugated linolei c acid, (n-3) fatty acids (particularly docosahexaenoic acid), and transvac cenic acid. Concentrations of docosahexaenoic acid were greater (P < 0.01) in milk fat from cows fed protected algae compared to milk fat from cows fe d unprotected algae. Milk fat from cows fed algae contained lower (P < 0.05 ) concentrations of total saturated fatty acids compared to cows fed the co ntrol diet. In conclusion, milk fat can be modified through nutritional man agement of dairy cows to provide more favorable fatty acids for consumers.