Genetic relationships among taurine (Bos taurus) and zebu (Bos indicus) populations as revealed by blood groups and blood proteins

Genetic relationships among nine cattle populations (Bos indicus and Bos taurus) were investigated using blood group antigenic factors and biochemical loci, for a total of 46 polymorphisms. All the analysed breeds live in hot climatesof Africa (Azaouak, Adamawa-Gudali, Small East African Zebu, Surqo, Brown Atlas, N'Dama, Somba), Central America (Carora), and Italy (Modicana). The study was carried out on 891 unrelated animals. Average heterozygosity ranged between 0.25 and 0.31 and showed higher values in B. indicus (zebu) populations (Azaouak, Adamawa-Gudali, Small East African Zebu, Surqo). Genetic distances between breeds were used for dendrogram construction. Two main clusters shared B. taurus and B. indicus. Within taurine (B. taurus) breeds, European or European like taurine populations (Modicana, Brown Atlas and Carora) clustered together, most probably because of the consistent presence of Brown Swiss genes in all of them. Another cluster involved the two African taurine populations (N'Dama and Somba). Multivariate analyses (Principal Component Analysis, Correspondence Analysis) of the allelic frequencies confirmed the breed clustering obtained. Overall relationships among breeds reflected remarkable genetic affinity between some of them.