Rising global temperatures are increasing heat stress in farm animals, causing suffering, production losses, and mortality. Climate adaptation in agriculture has urgent welfare dimensions.
Heat stress in livestock causes genuine suffering that spans a spectrum from mild discomfort to death. At moderate levels, heat stress causes reduced feed intake - animals literally experience hunger as a heat coping strategy. This leads to metabolic acidosis in ruminants as they eat less fiber, causing digestive discomfort. At higher temperatures, behavioral indicators of distress become clear - panting, bunching, reduced movement. Severe heat stress results in hyperthermia with organ damage, seizures, and death. The climate change projection that heat stress days will increase substantially in major livestock-producing regions means this welfare crisis will worsen without deliberate adaptation measures.