Extreme heat events pose serious welfare threats to livestock, and proactive heat stress management can prevent significant suffering and mortality.
Heat stress in farm animals causes significant welfare harm ranging from reduced productivity and compromised immune function at moderate levels to acute suffering and death at extreme temperatures. Poultry are especially vulnerable - birds in inadequately ventilated houses during heat waves can die in mass mortality events numbering in the millions during single events. Pigs, without functional sweat glands, require wallowing or spray cooling to thermoregulate effectively. Dairy cows experiencing heat stress reduce feed intake, produce less milk, and have compromised reproductive performance - each indicating an animal not functioning at physiological capacity due to thermal burden. As climate change intensifies heat events, the welfare importance of heat stress management infrastructure increases. Provision of adequate shade, ventilation, evaporative cooling, and continuous water access are fundamental welfare requirements during hot periods.