Heat stress in dairy cattle causes severe welfare harm through reduced feed intake, elevated core temperature, and chronic physiological stress, requiring active management through shade, ventilation, and cooling systems.
Heat stress in dairy cattle creates a cascade of welfare problems that compound each other. Cows that are heat-stressed reduce feed intake, altering rumen function and metabolic status in ways that predispose to metabolic disease. Reduced lying time from behavioral heat avoidance causes increased standing on concrete — a primary driver of the increased lameness observed in summer. Elevated core temperature during early pregnancy affects embryo survival, causing pregnancy loss and reproductive failure that has its own welfare dimension for subsequent calves. Effective heat abatement — combining shade, forced ventilation, and evaporative cooling — addresses these problems simultaneously. Sprinkler systems that intermittently wet the cow's back allow evaporative cooling that can reduce core temperature to near-thermoneutral zone levels even in hot, humid conditions. The economic case for heat abatement investment is exceptionally strong — reduced milk production, fertility loss, and increased disease burden in unmanaged herds far exceed the cost of cooling infrastructure. Welfare and productivity are aligned here in a way that should encourage adoption even in primarily production-focused operations.