RATE OF DISCHARGE AND MORPHOLOGY OF SWEAT GLANDS IN THE PERINEAL, LUMBODORSAL AND SCROTAL SKIN OF CATTLE

The rates of evaporation of moisture from the skin in the lumbodorsal, perineal and scrotal regions of cattle were measured in thermoneutral and high environmental temperatures. The rates of evaporation from the perineal and scrotal regions of heifers and bulls were significantly (P<0.001) greater than those from the lumbodorsal areas. The lumbodorsal rate of evaporation increased significantly (P<0.001) when cows and bulls were transferred from a thermoneutral to a hot environment and the rate of evaporation from the scrotum of bulls showed a similar increase; the rate of evaporation from the perineum of cows increased to a smaller extent (P<0.05) under the same conditions. The rate of evaporation from the perineum of cows reached a maximum on the day of oestrus but the stage of the oestrous cycle had no effect on the lumbodorsal rate of evaporation.