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

Abstract

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