Dietary Schizochytrium Microalgae Affect the Fatty Acid Profile of Goat Milk: Quantification of Docosahexaenoic Acid (DHA) and Its Distribution at Sn-2 Position.

The objective of this study was to detect the influence of dietary Schizochytrium microalgae on milk composition, milk fatty acids, and milk sn-2 fatty acids in goat's milk. Firstly, we could see that the fat content increased in low microalgae supplementation goat's milk (LM, 15 g/day) and the lactose content decreased in medium microalgae supplementation goat's milk (MM, 25 g/day) compared with control goat's milk (C, 0 g/day). Moreover, the absolute concentration of the docosahexaenoic acid (DHA) of LM, MM, and high microalgae supplementation (HM, 35 g/day) goat's milk was 29.485, 32.351, and 24.817 mg/100 g raw milk, respectively, which were all higher than that in the control goat's milk with 4.668 mg/100 g raw milk. In addition, the sn-2 DHA content increased in MM and HM goat's milk. However, the decreasing trend of the sn-2 DHA content was observed in LM goat's milk. As for other fatty acids, the oleic acid (C18:1n9c) and linolenic acid (C18:3n3) content decreased and increased, respectively, in all experimental goat milk. Finally, an interesting phenomenon was found, which was that docosanoic acid (C22:0) and tetracosenic acid (C24:1) were only detected in test goat's milk. Consequently, the phenomena of this study demonstrated that dietary Schizochytrium microalgae have an obvious effect on the fatty acid and sn-2 fatty acid profile of goat's milk, and they provide an effective method to improve the content of goat's milk DHA in practical production.