Effect of heat stress on dairy cow production, reproduction, health, and potential mitigation strategies

Extreme weather events are becoming more common and more severe as a result of climate change, and this has serious implications for the future of livestock, farmer income and livelihoods, and food security worldwide. Dairy cattle have become more heat sensitive due to selective breeding for higher production and increased feedlot operations. The harmful effects of heat stress cause hyperthermia, oxidative stress, and other physiological changes in dairy cows. Environmental heat stress causes a decrease in feed intake, leading to a decrease in milk production in dairy cows. The main method to check for reductions in milk production in dairy cows during the summer is an accurate evaluation of heat stress and effective mitigation strategies. Three primary management strategies have been proposed to reduce heat stress and stabilize dairy cattle performance in increasingly hot and humid climates. Short-term management options include physical alteration of the environment and nutritional management, while long-term management strategy includes discovering heat-tolerant genetic traits and genomic selection for heat tolerance. This review looks at how heat stress has affected the dairy industry’s sustainability and elaborates on genomic selection for thermotolerance in dairy cattle as sustainable breeding practices to increase dairy cows’ ability to withstand high temperatures.