GENE-FREQUENCIES OF CAPRINE ALPHA(S1)-CASEIN POLYMORPHISM IN SPANISH GOAT BREEDS

Using electrophoretic techniques (PAGE-SDS and IEF), we report allelic frequencies of caprine alpha(sl)-casein (Cn) locus in four Spanish mi lking breeds: Murciana-Granadina, Malaguena, Payoya and Canaria. The E allele (intermediate content of alpha(sl)-Cn in milk) was predominant in dairy breeds Murciana-Granadina. E:0.59; Malaguena, E:0.65 and Pay oya, E:0.76, while alleles A and B (high content of alpha(sl)-Cn) were more frequent in the Canaria dairy breed (A:0.28 and B:0.32). Among t he Spanish breeds, Canaria represents a particular case where 60% of t he alleles were of the high type (A and B), The ethnical group Canaria Palmera was particularly high in the frequency of alleles A and B (91 %) very similar to the Italian Garganica breed (98%). The low frequenc y of F allele (reduced level of alpha(sl)-Cn) in Spanish breeds (Murci ana-Granadina, F:0.08; Malaguena, F:0.04; Payoya, F:0.00 and Canaria, F:0.00) contrasts with the predominance of this allele in Alpine and S aanen breeds, It is important to note that in the Payoya breed no low or null alleles (F, D, 0) were detected, It seems unlikely that geneti c selection for milk production has had a significant influence in det ermining the alpha(sl)-Cn allelic distribution in goat populations. Th e direct relationship existing between these allelic variants and diff erences in the Cn content and in the physico-chemical properties of mi lk, can be used as a tool in the improvement of milk processing qualit y and cheese yields of Spanish milking breeds.