Effect of micro-alga supplementation on goat and cow milk fatty acid composition

Abstract

The microalgae cultivation has been developed over the last decades because it is capable of producing valuable metabolites, such as n-3 fatty acids for nutraceutical purposes. Aim of this study was to investigate the effect of the micro-alga as fat supplement on fatty acid profile of goat and cow milk, with particular reference to n-3 fatty acids and rumenic acid. Twenty dairy goats and 16 dairy cows were randomly allocated to two isonitrogenous treatment groups to investigate the effect of micro-alga supplementation on the composition and fatty acid profile of milk. The 1 st goat group was fed with alfalfa hay and concentrate; the 2 nd goat group received the same forages but the concentrate was supplemented with 10 g kg -1 DM intake micro-alga. The control group cows were fed with alfalfa hay, corn silage and concentrate, while the experimental animals were fed with the same forages but the concentrate was supplemented with 7.4 g kg -1 DM intake micro-alga. The experimental periods lasted for 17 d. The micro-alga supplements considerably increased rumenic acid concentration in milk (1.20% vs. 1.54%, P < 0.001 for goats; 0.75% vs. 0.85%, P < 0.05 for cows). The n-3 fatty acids were higher in milk (1.02 vs. 1.35; P < 0.001 for goats; 0.47 vs. 0.56; P < 0.05 for cows) and in addition the n-6/n-3 ratio was also more favorable in the micro-alga supplemented groups (3.53 vs. 2.88; P < 0.01 for goats; 4.18 vs. 3.36; P < 0.05 for cows). It is concluded that the diet with micro-alga supplementation significantly increased the concentration of beneficial fatty acids in both goat and cow milk.