Heat stress affects every stage of the cow cycle

Emerging evidence indicates that heat stress profoundly affects calves and cows from the prenatal stage through lactation. As global temperatures rise, so does heat stress in dairy production. Heat stress occurs when a cow’s ability to disperse heat produced through normal metabolism is compromised, which usually happens when the ambient temperature exceeds the thermoneutral zone (TNZ). The TNZ is defined as the temperature range in which an animal maintains normal body temperature without al