Polymorphisms in Caseins of Sheep Milk

Abstract

Starch gel electrophoresis of 592 sheep milk samples including six breeds or crosses between these breeds revealed two variant casein types, one a-s₁ and one β casein. The number of variants found was low being, .036 and .017 for a_s1-casein and β-casein types, respectively. The predominant type for a_s1-casein had three brands, whereas, the variant type had six bands. A previously reported a_s1-casein variant was found to be one of the whey proteins as it was absent in reconstituted casein samples subjected to electrophoresis. There were three bands in the β-casein region of the predominant type. The variant β-casein type appeared to have a lighter fourth band. The frequency of the β-casein variant allele was .017. Sheep milk could be typed on gels of low pH with precision equal to that of alkaline gels. Acid gels did not reveal additional heterogeneity. Copyright © 1973. American Society of Animal Science . Copyright 1973 by American Society of Animal Science.