Indoor housed dairy and beef cattle are increasingly vulnerable to heat stress during UK summer heatwaves, with welfare impacts on health, productivity, and reproductive success.
Cattle experiencing heat stress show a range of welfare-compromising behaviors and physiological responses. Panting, increased respiratory rate, and reduced feed intake are early signs. As heat stress increases, cattle crowd around water troughs, seek any available shade, and spend less time lying, which reduces rumen function and increases lameness risk. Severe heat stress can cause prostration and death if cooling is not provided. Dairy cows generate more metabolic heat than beef cattle and high-producing cows are most vulnerable. The welfare impact of heat stress in poorly ventilated buildings is acute and can affect entire housed herds simultaneously during heatwaves.