Med. Weter. 69 (11), 666-669, 2013

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Strza?kowska N., Markiewicz-K?szycka M., Bagnicka E., Po?awska E., Krzy?ewski J.
Influence of polymorphism of casein proteins on chemical composition and technological properties of goat?s milk
Casein is the predominant protein in milk of almost all mammalian species. The goat casein fractions (?S1-, ?-, ?S2 -, ?-casein) are coded by the single autosomal genes CSN1S1, CSN2, CSN1S2, and CSN3, which cluster in a DNA segment of about 250 kbp, mapped to chromosome 6. All casein fractions are characterized by high variability. At the four loci, ?normal? alleles are associated with a normal or high casein fraction content, whereas ?defective? alleles are associated with a medium, low, or zero content of casein fraction in milk. The quality of total casein and, in particular, the calcium-sensitive fraction (?S1-, ?-, ?S2) significantly affects the chemical, physical, technological, and nutritional quality of goat?s milk.
Key words: goat, casein, protein, milk