Feeding and managing cows to minimize heat stress.

Abstract

Environmental-induced hyperthermia compromises e cient animal production and jeopardizes animal welfare. Reduced productive output during heat stress was traditionally thought to result from decreased nutrient intake. Our observations challenge this dogma and indicate heat-stressed animals employ novel homeorhetic strategies to direct metabolic and fuel selection priorities independently of nutrient intake or energy balance. Thus, the heat stress response markedly alters post-absorptive carbohydrate, lipid, and protein metabolism, independently of reduced feed intake through coordinated changes in fuel supply and utilization by multiple tissues. There may be nutritional, pharmaceutical, and managerial options to take advantage of these aforementioned metabolic changes to improve productivity and animal welfare during the warm summer months.