Effect of Air Velocity on the Heat Losses of Sheep and Cattle

Abstract

EXPERIMENTS in respiration chambers in which the ambient air temperature could be accurately controlled showed that the air temperature below which heat production increases in response to a fall in air temperature is in calves 13° C (ref. 1), in adult cattle 7° C (ref. 2) and in sheep with 4-cm fleece 8° C (ref. 3). In these experiments air movement was less than 0.5 m.p.h., being that induced by the circulating fans in the chambers. Little information is available about the effect of air movement on the heat losses of sheep and cattle. Alexander⁴ has shown, however, very large increases in heat production when lambs are exposed to the blast of a fan and large metabolic effects have been noted in infant caribou exposed to cold windy conditions⁵. Many practical observations show that the production of cattle and sheep, and indeed their very survival, is adversely affected by cold winds.