EFFICIENCY OF USING MALES OF DIFFERENT GENOTYPES AS PARENTAL FORM OF THE CROSS

Introduction. Rabbit meat production can be an important element in solving the problem of lack of dietary protein for the growing human population all over the world, especially in developing countries. Compared to other types of animals, the advantage of rabbits is that rabbit meat has a high protein content and low fat and cholesterol content, has excellent taste qualities, and is a product of healthy and dietary nutrition. Using crossbreeding increase the productivity of rabbits due to the effect of heterosis. However, taking into account the fact that the modern technology of industrial rabbit breeding involves the use of rabbits of various crosses, which are imported into our country, there is a need to investigate the possibility of using males of different genotypes as the parent form of the cross and their influence on the reproductive characteristics of female rabbits. Thus, the purpose of the study was to study the selection characteristics of males of different genotypes and the effectiveness of their use as parental forms of the cross. Materials and methods of research. The research was carried out in the conditions of "Krolikoff Farm" LLC, which is located in the Uman district of the Cherkasy region, during 2022. The research was conducted using males of four genotypes: males of the parent form of the Hyla – Hyla Max cross (HM, n = 15), males of the parent form of the Hyplus PS59 cross (PS59, n = 15), males of the Termon white breed (TB, n = 12), males of the Poltava silver breed (PS, n = 9). Males were used on female rabbits of the maternal form of the Hyla – Hyla NG cross, from which 4 groups were formed, depending on the genotype of the breeder, with the sperm of which the female rabbits were inseminated. Females of group I were inseminated with sperm of Hyla Max males, group II – Hyplus PS59, group III – Termon white breed, group IV – Poltava silver breed. The females of the experimental groups were similar in age, live weight, and number of hatchlings. Research results. Analyzing the results of research on the productivity characteristics of males of different genotypes, it was established that males of the Hyplus PS59 parental form had the highest live weight, it was 0.41 kg more (p ≤ 0.001) than males of the Hyla – Hyla Max parental form. The live weight of the males of the Termon white breed was 14% lower (p ≤ 0.001), and that of the males of the Poltava silver breed was 18% lower (p ≤ 0.001) than that of the Hyla Max males. This fact can be explained by the implementation of directed selection work with males of the original lines of crosses based on live weight indicators. Hyla Max males had the highest ejaculate volume values. However, it should be noted that the males of the Thermon white breed were slightly inferior to the males of the parent form of the Hyla cross in terms of this indicator. Males of the Poltava silver breed had the lowest value of ejaculate volume. As a result of the research, it was established that female rabbits inseminated with the sperm of Hyla Max males had the highest litter size. Rabbit does inseminated with PS59 males had 5.6% lower fertility than female rabbits inseminated with Hyla Max males, and rabbits inseminated with Termon White males had a 6.9% lower fertility rate. The highest value of high fertility was recorded in female rabbits inseminated with the sperm of PS59 males. There was no significant difference between the high fertility of female rabbits on which Hyla Max males and Termon white males were used. Female rabbits inseminated with males of the Poltava silver breed had the lowest fertility. Conclusions. According to the results of the conducted research, it can be stated that the most effective as a parent form of the cross is the use of Hyla Max males, however, the use of males of the Termon white breed of rabbits as a parent form of the cross is expedient due to the high cost of imported cross males. At the same time, the productivity of female rabbits remains at a high level, and according to some signs, female rabbits on which cross males were used prevail.