Studies of the cattle of Northern Rhodesia: II. The apocrine gland population of the skin of Northern Rhodesian cattle and its connexion with the heat toleration coefficient

Abstract

An investigation has been undertaken to study the apocrine gland population of the skin of the three indigenous breeds of cattle native to Northern Rhodesia, and a comparison made between them and the Africander.It was found that the Angoni had the greatest density of glands/sq.cm. and that this density agreed closely with mean figures quoted for Bos indicus. The Barotse and the Tonga, both Sanga types, had significantly lower gland density, but were both significantly greater than the Africander which is a relict Zebu form.Dowling's finding that the decrease in the density of the glands with age is due to the ‘spread’ of the constant number laid down at birth by the growth of the skin was confirmed.A very close correlation between the density of the apocrine glands and the heat toleration coefficient was established.From a consideration of previous work, it is concluded that the density of the apocrine gland population is only one of the factors concerned in the control of thermo-neutrality by cattle; in this there is some disagreement with the conclusions reached by Australian workers.