Heat stress in dairy cows causes significant welfare harm, reduces milk production, and increases disease susceptibility — making it both a welfare and economic priority as global temperatures rise.
Dairy cow heat stress is an acute welfare problem that intensifies with climate warming. High-producing dairy cows generate substantial metabolic heat and have limited thermoregulatory capacity in humid conditions, making them more susceptible to heat stress than lower-producing animals. Welfare impacts — reduced feed intake, increased respiratory rate, elevated body temperature — occur well below temperatures that humans find uncomfortable. Effective cooling infrastructure, access to shade, and appropriate stocking density management reduce welfare harm. As climate warming extends heat stress seasons and intensifies peak events, investment in cooling infrastructure becomes increasingly necessary for basic welfare compliance.