Impact of Microalgae Supplementation on Milk Production Parameters: A Meta-Analysis

Numerous studies have suggested controversial findings regarding the impact of microalgae on dairy cows’ production parameters. This meta-analysis aimed to investigate the overall effects of microalgae on dairy cows’ performance and milk fatty acids and to highlight variation factors inducing opposite findings in the impact of microalgae on dairy cow nutrition. Following the PRISMA guidelines, articles examining the influence of microalgae on dairy cows’ performance and milk fatty acids were searched through Google Scholar, Web of Science, Science Direct, and Scopus. As a result, 10 articles were selected and categorized into 18 experiments for inclusion in our meta-analysis. The results suggested significant increasing effects (p < 0.05) of microalgae on milk yield and rumenic acid, while decreasing effects (p < 0.05) were observed in caproic acid, caprylic acid, capric acid, lauric acid, pentadecanoic acid, and myristic acid. The sub-group analysis suggested that the Aurantiochytrium limacinum microalgae strain showed more consistent effects compared with other evaluated strains. Thus, the present meta-analysis makes a valuable contribution to comprehending the beneficial effect of microalgae in dairy cow nutrition and the factors that may influence the impact of this sustainable feed additive on milk production and quality.