The influence of the multiplicity of use of donor-cows to the exit of the oocyte-cumulus complexes
It is known that with the development of artificial insemination technology, which allowed tens of thousands of descendants to be obtained from one producer, the role of bulls in improving the herd has increased dramatically. At the same time, the role of the uterus remained at the same level. Under the conditions of industrial technology, over the entire productive life, it can produce from 3 to 6 calves, while in their ovaries there are tens of thousands of potential eggs.Thisarticle presents the results of studies conducted in the Republic of Belarus for the first time on the influence of biological factors of direct and indirect influence on the efficiency of obtaining oocytes in the system of transvaginal aspiration. According to the results of studies, there were no significant differences in the effect of the number of aspiration on the oocyte yield. The greatest number of oocytes of excellent and good quality was observed in a group of animals whose aspiration was carried out once a week and amounted to 24.1%. The level of extractability of oocytes with the frequency of extraction every 7 days decreased compared with the frequency of extraction in 3 days by 10.0 p. p. at the Same time, the yield of oocytes of excellent and good quality increased slightly (by 4.5 p. p. as well as the yield of suitable cells in General - by 2.9 p. p.) and was within the error. By the number of extracted oocytes 78% of animals showed higher results after 7 days. In donors with the number of aspiration from 20 to 30, the yield of viable cells increased to 84.4%. The data obtained are of practical importance for development of technology for in vitro embryo production in the system of transvaginal aspiration of oocytes which will help to accelerate breeding process and increase efficiency of breeding work in livestock production in general.