Scrotal thermoregulation of the bull (Bos sp.)

Abstract

A comparison was made of evaporative heat loss from the skin of the scrotum and the thorax of the bull. The sweat glands of the scrotum were not controlled independently of those on the general body surface. Scrotal sweat glands were found to be under adrenergic neural control like those of the general body surface. The large sweat glands of the scrotum produced approximately five times as much sweat per gland as those on the general body surface. Localized heating of the scrotum for 20 min stimulated both panting and sweating without any change in deep body temperature. Insensible moisture loss from the scrotum was greater than that from the skin of the general body surface. It is concluded that there are no fundamental differences in the properties of the sweat glands of the scrotum and those of the general body surface, and that the high insensible moisture loss of the scrotum assists with cooling of the skin of the scrotum. It is suggested that a function of the tunica dartos muscle is to reduce insensible moisture loss.