Sweating in cattle. II. Cutaneous evaporative loss measured from limited areas and its relationship with skin, rectal, and air temperatures

Abstract

1. Three female calves (Shorthorn, Zebux Australian Illawara Shorthorn, and American Brahman) of about 7–8 months old were exposed to different combinations of wet- and dry-bulb temperatures in the psychrometric chamber at the Physiology Department of the University of Queensland.2. A capsule method has been developed for measurement of cutaneous evaporation from limited areas. This method has been described in detail.3. Cutaneous evaporation from the shoulder area of the Zebu cross was significantly higher than that of the Shorthorn. There was, however, no difference between the two animals in their cutaneous evaporation from the belly area.4. In the Zebu cross the cutaneous water losses from the shoulder area, on the average, increased linearly with increase in skin temperature. In the Shorthorn, there was no important increase in the cutaneous evaporation from the shoulder area, although the skin temperature increased by about 2–3/ F.5. The Zebu cross had lower skin temperatures of the shoulder area when compared with that of the Shorthorn. These lower skin temperatures were associated with higher cutaneous evaporation.6. Increase in rectal temperature was not accompanied by increase in cutaneous evaporation in all the three animals studied.7. In all the three calves the cutaneous evaporation increased with increase in air temperature.