Effect of environmental temperature and humidity on milk production and milk composition of Guanzhong dairy goats

The present study was undertaken with the aim to examine the relationship between temperature and humidity and milk production traits in Guanzhong dairy goats reared in China, and to assess the possibility of future genetic selection in dairy goats for increased tolerance to adverse environmental conditions, thereby improving goat farm management in China. Production data included 149 Guanzhong dairy goats with the first-lactation collected throughout 2019. The traits investigated were milk yield, and indicators of milk composition of Guanzhong dairy goats. For high temperature, significant and marked daily milk yield drops, up to 16% (about 0.23 kg/d per head) were observed in July and August when compared with the other months. The fat content, protein content, and dry matter were significantly lower in July and August. Importantly, milk production traits present significant correlations with high temperature, while high humidity had little effect on milk composition of Guanzhong dairy goats. Therefore, the adverse environmental conditions on farm profit is not negligible, and the strategies could be improving the goat farm management as well as obtaining thermotolerant animals through genetic selection.