Livestock Welfare in Extreme Heat

Climate change is increasing the frequency and severity of heat stress events in livestock; proactive management protects animal welfare during heatwaves.

Key Facts

Cattle show heat stress above approximately 22 degrees Celsius combined with high humidity.
Pigs, lacking functional sweat glands, are highly vulnerable to heat stress above 25 degrees Celsius.
Poultry suffer heat-related mortality at temperatures above 30 degrees Celsius without adequate cooling.
Heat stress causes reduced feed intake, reproductive failure, immune suppression, and death.
The Temperature-Humidity Index (THI) is a standard tool for assessing heat stress risk in cattle.

Welfare Considerations

Heat stress causes acute suffering in livestock through hyperthermia, respiratory distress, cardiovascular strain, and in severe cases death. UK livestock farmers have increasingly experienced significant heat events that challenge housing designed for a cooler climate. Welfare interventions include shade provision (essential), high-volume ventilation or tunnel fans, misting systems, provision of cool clean water at all times, and reduced stocking density during heat events. Reducing high-energy concentrate feeding during heatwaves lowers metabolic heat production. Pre-emptive action before forecast heatwaves is more effective than reactive management once animals are already stressed.

What You Can Do

Develop a heatwave action plan with your vet and advisor before summer each year.
Ensure adequate shade, ventilation, and water access as permanent infrastructure for all livestock.
Reduce stocking density and concentrate feeding proactively during forecast high-temperature periods.
Monitor animals closely during heat events for signs of heat stress and act immediately.