Transfer Rates of Docosahexaenoic and Eicosapentaenoic Acids into Cow's Milk in Pasture Based and Feed-Lot Management Systems

Abstract

The aim of the research is to assess the transfer of docosahexaenoic (DHA) and eicosapentaenoic (EPA) into cow's milk following supplementation with rumen protected fat supplements (rumen protected omega fat, RPOF). In pasture based and in feed-lot management systems the transfer of DHA and EPA is 19-20% following supplementation with equal proportions of DHA and EPA (20-25 g/cow/day); the DHA and EPA level in milk are at 0.4% of the total fatty acids for each. There is no change in milk yield, protein, and fat content after 60 and 105 days of RPOF supplementation in pasture based and lot fed cows, respectively. The transfer of DHA into milk fat is around 25-32% when RPOF containing higher proportions of this fatty acid are fed (40.8 g/cow/day) and the DHA content in milk is about 1% of the total fatty acids. Practical Applications: Significant quantity of omega 3 DHA and EPA can be transferred into cow's milk in pasture based and feedlot management systems, and there is no reduction in milk yield, fat, and protein content. Furthermore, omega 3 milk with varying proportions of DHA and EPA can be produced in different dairy enterprises.