Frequency of αS1-casein variants in the Italian goat breeds Sarda and Verzaschese

The alpha(s1)-casein pattern was studied in 104 individual milk samples from goats of the Italian breeds Verzaschese and Sarda. Analysis of the alpha(s1)-casein variants was performed by combining isoelectric focusing and reverse-phase HPLC. The most frequent alpha(s1)-casein variants in Sarda goats were the "strong" A and B variants. The majority of Verzaschese goats bore the "weak" F variant, and B was the only strong variant in this breed. In both breeds, the total casein content was correlated to the variant distribution. This finding could be useful for rapid screening purposes, given the different technological properties of goat milks containing different alpha(s1)-casein variants.