Heat Stress Management in Dairy Cattle

Heat stress is a major welfare and production concern for dairy cattle, causing reduced milk yield, reproductive failure, and chronic physiological stress in hot climates.

Key Facts

Dairy cows become heat stressed at temperatures above 25 degrees Celsius
Heat stress reduces milk production by 10-20% and impairs reproduction significantly
Housed cows in poorly ventilated buildings suffer even in temperate climates
Shade, water access, and cooling systems can substantially mitigate heat stress effects
Climate change is expanding the geographical range and duration of heat stress periods

Welfare Considerations

Heat-stressed dairy cows exhibit classic indicators of poor welfare including increased panting, reduced feed intake, crowding around water sources, and abnormal postures. Chronic heat stress suppresses immune function, making cows more susceptible to mastitis and other infections. The welfare impact is compounded in high-yielding breeds that produce more metabolic heat. Farms in temperate regions that historically did not need cooling infrastructure now face increasing welfare obligations as summer temperatures rise.

What You Can Do

Support dairy welfare standards that require shade and cooling for housed cattle
Choose dairy products from farms with demonstrated heat stress mitigation measures
Advocate for building regulations that require adequate ventilation in livestock housing
Support research into heat-tolerant dairy breeds with good welfare characteristics
Reduce dairy consumption or choose products from farms in cooler climates