Journal of Fisheries & Livestock Production
Open Access

Abstract

In sheep, the polymorphism of major milk proteins is reduced as compared with other ruminant species like cattle and goats. As in other ruminant species, in sheep these polymorphisms were studied relative to milk quantity, quality and its manufacturing properties or for authenticity identification of dairy products. In Algeria, data concerning the characterization of the sheep breeds in the six loci codifying for major milk proteins genes are almost absent. The purpose of our study was to determine milk quality indices as well as milk protein polymorphism in local sheep breed using 60 samples of milk from two local sheep breeds Hamra and Ouled Djellal. Our work consisted in the isolation and characterization of milk proteins. For this, we used the precipitation of caseins Phi [pH 4.6]. After extraction, purification and assay both casein and serum protein fractions were then assayed by the Bradford method and controlled by polyacrylamide gel electrophoresis (PAGE) in the different conditions (native in the presence of urea and in the presence of SDS). The electrophoretic pattern of milk samples showed the presence similarities of four major caseins variants (αs1-, αs2-β-and k-casein) and two whey proteins (β-lactoglobulin, α-lactalbumin) of two races Hamra and Ouled Djellal. But compared to bovine milk, they have helped to highlight some peculiarities as related to serum proteins (α La β Lg) as caseins including αs1-Cn.

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