The significance of the coat in heat tolerance of cattle

Abstract

The heat tolerance of two strains of cattle, one with a strongly medullated coat, was measured with aid without previous clipping and with and without a plastic coat. The results supported the hypothesis that the difference in heat tolerance of the same animal at different seasons can be attributed to correspond in changes in the hair coat. Animals in a long, woolly winter coat were not heat-tolerant, whereas the same animals clipped were. Animals in a medullated coat were relatively heat-tolerant, both clipped and unclipped. Clipping improved their temperature control to some extent, but the difference made by clipping was nowhere as great as in animals with a non-medullated coat.