Heat Stress in Pigs: Recognition and Prevention

Pigs are highly susceptible to heat stress due to limited sweat glands, and effective thermal management is critical on farms in warm climates.

Key Facts

Pigs have very few functional sweat glands and rely on panting and wallowing to cool down
The upper critical temperature for pigs is approximately 25-27 degrees Celsius
Heat stress reduces feed intake, growth rate, and reproductive performance
Pregnant sows are particularly vulnerable, with heat stress reducing litter size
Evaporative cooling, sprinklers, and shade significantly reduce heat load
Water intake increases by 50% or more during heat stress
Heat stroke can cause death within hours if animals are not cooled

Welfare Considerations

Heat stress causes profound suffering in pigs - panting, lethargy, prostration, and cardiovascular strain. It affects immune function, increases disease susceptibility, and compromises reproductive welfare. High-density housing in hot conditions is a serious welfare concern. Providing adequate space, water, shade, and cooling systems is not optional but fundamental to meeting basic welfare standards.

What You Can Do

Ensure continuous access to abundant cool, fresh water during hot weather
Install sprinkler or misting systems in pig housing
Reduce stocking density during heat waves
Avoid moving or handling pigs during the hottest part of the day
Monitor pigs closely for signs of heat stress and act quickly if observed