Heat stress in dairy cattle: mechanisms, welfare indicators and practical mitigation
Background: Heat load is a growing constraint on dairy cattle health, welfare and productivity.
Approach: This narrative review integrates established physiological and welfare literature with practical mitigation principles.
Key findings: Heat stress alters thermoregulation, feeding behaviour, endocrine function and rumen performance. Respiration rate, panting, body temperature, shade use and production records should be interpreted together. Shade, ventilation, effective evaporative cooling, reliable drinking water and ration management form a layered response.
Conclusion: Heat-abatement plans should be triggered early, monitored with animal-based indicators and adapted to local humidity, housing and herd risk.