Lifetime productivity of bulls depending on the similarity of their parents by antigens of the B blood group system

During the selection of parents future bulls meat breeds, problem improving main signs productivity is a priority. Search for techniques that would additionally influence effectiveness using conventional breeding methods determines relevance this study. The purpose study was to determine parent pairs based on antigens B blood group system results lifelong use Ukrainian beef cattle, created by method complex reproductive crossing four different breeds. conducted comparing performance assigned groups antigenic similarity index (ras) their parents. By ras value over 0.150 formed progenies from homogeneous (n=5). In heterogeneous (n=5), indicator less than 0.150. libido tested in arena time manifestation sexual reflexes when receiving sperm an artificial vagina. Within groups, age at first collection, life and productive use, number ejaculates received culled, quality fertilising ability were determined. It identified obtained compared peers mating, there tendency increase initiation collection 33.9%. They also have longer expectancy 6.3% 21.5%. Bulls during more leads scarecrow 13.6% predominate obtained. percentage ejaculate culled twice as high. higher (by 15.3 points) share active reflexes, larger volume ejaculate, better indicators motility concentration, fewer ejaculates, fertilisation capacity 18.2 points. should be used potential mothers valuable breed other livestock populations