CharaCteristiCs of phenogroups of the a blood group system in Cattle of beef breeds**

phenotypes of four beef breeds (Charolais, hereford, limousin and piemontese) were determined based on the transmission of antigens from parents to offspring in the a blood group system of cattle. the effective number of alleles per locus (e) and the degree of heterozygosity (h) were calculated for different breeds based on the frequency of these phenogroups. most a-phenogrups (18) were found in limousin cattle and least in Charolais and hereford cattle (12). a-phenogroups with the Z’ antigen, especially the a1Z’ phenogroup were characteristic of the breeds studied. the greatest variation in this blood group system was found in the limousin breed (e and h values of 9.7 and 0.8977, respectively) and the smallest variation in the hereford breed (7.0 and 0.8578, respectively). the identification of a-phenogroups and confirmation of the fact that the d antigen is only found in one phenogroup with the plb-8 antigen could be used for parentage verification of cattle of beef breeds.