Polymorphism of alpha(s)-caseins in the milk of two Spanish ovine breeds

A total of 288 individual milk casein (CN) samples from two Spanish autocht honous ovine breeds, Manchega and Segurena have been analyzed, and polymorp hism of the alpha(s)-casein complex has been detected. High resolution was obtained with ultrathin gels isoelectric focusing allowing the identificati on of a,l-CN alleles A, B, and C. Six alpha(s1)-CN genotypes were found in the Manchega breed (AA, AB, AC, BE, BC and CC), but only 3 genotypes were f ound in Segurena breed (AC, BC, and CC). alpha(s1)-CN E and D alleles (know n as Welsh variant) were not detected in the milk either breed analyzed. Th e allele frequencies were: A, 0.055; B 0.345; and C, 0.600, in Manchega bre ed and A, 0.020; B, 0.090, and C 0.890 in Segurena breed. Some ethnological considerations have also been discussed.