Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows.

Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows.