Heat stress is a major and growing welfare problem for cattle as global temperatures rise. Understanding the signs, thresholds, and prevention strategies helps farmers and advocates protect animal wellbeing.
Heat stress in cattle produces genuine suffering — elevated cortisol, respiratory alkalosis from panting, reduced movement, and altered behaviour reflect a state of significant thermal discomfort. In severe cases, heat stroke is fatal within hours. Chronic subclinical heat stress across a production season causes cumulative immune suppression, reproductive failure, and reduced calf vigour. Prevention is far more effective and welfare-positive than treatment: shade structures covering at minimum four square metres per cow, mechanical cooling fans, and water sprinkler systems reduce core body temperature and restore normal behaviour within hours. Access to clean, cool water is critical — heat-stressed cattle increase water intake three to four times above normal. Night-time cooling when temperatures drop is particularly valuable, as cattle radiate absorbed body heat most effectively in cooler night air. Housing design that promotes air flow and shade planning that follows sun movement provide passive cooling without energy cost.