Genetic variants of casein in Indian and African Zebu cattle

Abstract

1. 1. The caseins present in the milk of cows of five Indian and two East African Zebu breeds were examined by gel-electrophoretic procedures. 2. 2. Like those of Western breeds, the α s1 -, β- and κ-casein systems were polymorphic. 3. 3. Most of the genetic variants appeared to be identical to those seen in Western breeds, but a variant (β-casein B Z) of the same electrophoretic mobility as the β-casein B of Western cattle proved to be different in amino acid composition. 4. 4. A rare new variant, β-casein D, was found in the milk of Indian Deshi and East African Boran cows. 5. 5. Zebu breeds had a very high gene frequency of α s1 -casein C, in contrast to Western breeds in which the B-variant predominates. 6. 6. The East African milks were additionally examined for, but did not contain, β-lactoglobulin C, a variant characteristic for the Jersey breed.