Cattle Welfare During Summer Heat Stress

Climate change is increasing the frequency and severity of summer heat stress events for dairy and beef cattle. Heat stress causes measurable welfare and production impacts that require proactive management.

Key Facts

Dairy cows begin experiencing heat stress at temperatures above 21C with moderate humidity
Heat stress reduces milk yield by 10-35% in severely affected animals
Conception rates fall from 55% in thermoneutral conditions to 15-25% in heat stress
UK summers now regularly exceed heat stress thresholds previously uncommon
Friesian-Holstein dairy breeds are more heat-sensitive than beef breeds

Welfare Considerations

Cattle heat stress welfare impacts are physiological and measurable. Core body temperature above 39.5C causes reduced feed intake, reduced fertility, altered blood chemistry and immune function suppression. Cattle experiencing heat stress show increased panting, reduced rumination, standing preference (to maximise surface area for heat loss) and reduced feed intake. Shade provision is the single most effective welfare intervention — buildings, trees and purpose-built shade structures reduce core temperature by 1-2C in peak heat. Fans and sprinklers in housed cattle provide additional cooling. The welfare case for shade provision is reinforced by the economic case — heat-stressed cattle produce less milk and have lower conception rates.

What You Can Do

Ensure all cattle have access to shade during summer — trees, buildings or shade structures
Provide unlimited cool, clean water — heat-stressed cows drink 50-80% more than normal
Use fans and misters in housed cattle facilities during heat events
Delay housing until cooler evening temperatures during summer heat waves
Report severe cattle heat stress symptoms to your farm vet immediately