Heat stress in beef cattle is an increasingly significant welfare concern as climate change drives more frequent and severe summer heat events across the UK and globally. While beef cattle are generally more heat-tolerant than high-yielding dairy cows, heat stress still causes significant welfare compromise, production losses, and increased disease susceptibility.
Heat Stress Thresholds
The temperature-humidity index (THI) provides a combined measure of heat and humidity load. Beef cattle typically begin experiencing thermal discomfort above a THI of 72 (approximately 22°C at moderate humidity). Continental and tropical breeds (Charolais, Limousin, Simmental) tend to be more heat-tolerant than British native breeds (Hereford, Angus). Dark-coloured cattle absorb more solar radiation than light-coloured animals.
Increased time spent standing (to maximise body surface area exposure)
Reduced feed intake and growth rate
Management Strategies
Shade: Natural shade from trees is most effective; artificial shade structures should provide minimum 4m² per animal. Shade positioned to block afternoon sun (from the west) is most beneficial.
Water: Water intake increases dramatically in heat stress; adequate clean water supply is critical. Provide 10cm trough space per animal; check supply pressure and delivery rate in hot weather.
Grazing management: Move cattle to fresh pasture in early morning or late evening; avoid muster and handling during the hottest part of the day.
Ventilation in housed systems: Natural ventilation design (ridge and eave openings) and mechanical fans significantly reduce heat load in housed finishing systems.
Feed management: Adjust feeding times to cooler periods; total mixed ration (TMR) fed in early morning and evening reduces heat generated during digestion.