Use of omega‐3 fatty acid rich algae and their oil as a feed supplement for dairy cattle

Abstract

Our objective was to examine use of algal biomass as an omega‐3 fatty acid‐enriched ration supplement for dairy cattle. Rations of four lactating cows were supplemented with 1X or 0.5X rumen protected (RP) algal biomass supplement, 1X RP algal oil supplement, or no supplement in a 4×4 Latin Square design. Supplements were lipid encapsulated (Balchem Corp., New Hampton, NY). 1X supplements provided 29 g/d docosahexaenoic acid (DHA). Supplementing dairy rations with rumen protected algal supplements did not affect feed intake, milk yield, or milk composition (P>0.05). Both 0.5X and 1X RP algae supplements increased (P<0.01) daily milk fat yield of DHA (0.5 and 0.6±0.10 g/d, respectively) compared to 1X RP oil (0.3±0.10 g/d), but all supplements were greater (P<0.01) than control (0.1±0.10 g/d). Yield of trans‐18:1 fatty acids in milk fat was also increased by supplementation, suggesting supplements may have influenced rumen microflora. Trans‐11 18:1 yield (13, 20, 27, and 15±3.0 g/d for control, 0.5X RP algae, 1X RP algae, and 1X RP oil, respectively) was greater for supplements than control (P=0.05). Rumen protected algal biomass provided better DHA yield than algal oil.