Milk Yield, Composition, and Fatty Acid Profile in Milk of Dairy Cows Supplemented with Microalgae Schizochytrium sp.: A Meta-Analysis

This study aimed to evaluate the effects of the microalgae (MIAs) Schizochytrium sp. as a dietary supplement for dairy cows with respect to the yield, composition, and fatty acid profile of milk using a meta-analytical method. The data used in the statistical analyses were obtained from 11 peer-reviewed scientific publications. The effect size was assessed using the weighted mean differences (WMDs) between MIA-supplemented and control treatments. Dry matter intake, milk fat yield, and milk fat content decreased (p < 0.001) in response to the dietary inclusion of Schizochytrium sp. MIAs. However, Schizochytrium sp. MIAs supplementation increased (p = 0.029) milk yield. The dietary inclusion of Schizochytrium sp. MIAs decreased (p < 0.05) the content of the fatty acids (FAs) butyric, caproic, caprylic, capric, undecanoic, lauric, pentadecanoic, palmitic, heptadecanoic, stearic, arachidic, and total saturated FAs, and it resulted in a ω-6/ω-3 ratio in milk. In contrast, Schizochytrium sp. MIAs supplementation increased (p < 0.05) the content of linoleic, conjugated linoleic, eicosapentaenoic, behenic, docosahexaenoic, total monounsaturated FAs, total polyunsaturated FAs, and total omega-3 FAs in milk. The results showed that Schizochytrium sp. MIAs could be used as a dietary supplement to improve the milk yield and fatty acid profile of milk obtained from dairy cows.