Supplementary material: Meta-analysis of the effects of dietary interventions to alleviate heat stress in lactating dairy cows

Heat stress has become a serious issue in the dairy industry, directly affecting health, production, and economic losses. To alleviate these negative impacts, an increasing number of studies have examined the effects of feed additives and supplements on the lactation performance of dairy cows worldwide. Our study quantitatively summarized 53 publications that have been published to date. Overall, our results showed a positive response of greater lactational performance when certain feed additives were used, such as live yeast Saccharomyces cerevisiae and their co-products and phytochemicals, while supplementation with minerals and vitamins, such as Cr, Zn, and Niacin, exhibited limited or inconsistent effects.