An experimental study of heat tolerance of cattle

Abstract

The ability of cattle to maintain a normal body temperature in a dry, hot, inland Australian environment is associated with their ability to dissipate excess heat from the body. A heat tolerance test, based on rectal temperature responses after exercise, is reported. This test indicates the animal's capacity to lose heat. Forty animals, classified on their coat covering, were included in the experiments described. The differences in coat covering are described and associated with differences in rectal temperature under various forms of heat stress. The results serve to illustrate the basic weaknesses of any field test (or hot-room test) which cannot be carried out under conditions where major factors influencing the "adaptability" and type of coat can be kept uniform for all animals tested.