A Possible Explanation for Part of the Difference in Heat Tolerance Exhibited by Bos taurus, and Bos indicus Beef Cattle

Abstract

USING methods based on those described by Callow¹ the carcasses of 27 head of mature boran (Bos indicus) cattle were analysed. When the results of these analyses are compared with those of Callow² for Bos taurus (Fig. 1) it is evident that there is a marked and progressive difference in the way in which the two species lay down fat during the fattening period, as represented by a change of from 18 to 40 per cent total separable fat in the carcass. In Fig. 1, the percentage deposition of subcutaneous and inter-muscular fat of Bos taurus, and Bos indicus has been plotted against the percentage total separable fat in the carcass. In the case of Bos taurus the difference between the levels of subcutaneous and intermuscular fat tends to decrease as fattening proceeds whilst this difference for Bos indicus clearly increases over the same period.