TY - JOUR AU - S. O. Sidashova AU - V. F. Stachovsky AU - О. V. Shcherbak PY - 2019/04/24 Y2 - 2024/03/28 TI - RESEARCH OF LIVE MASS OF CALF–EMBRYOTRANSLANTANTS JF - Animal Breeding and Genetics JA - Anim. Breed. and Genet. VL - 57 IS - 0 SE - Reproduction DO - 10.31073/abg.57.22 UR - https://abg-journal.com/index.php/journal/article/view/236 AB - The efficiency of breeding and production processes in dairy cattle breeding are closely linked and limited by the genetic value of animals, their reproduction ratio, and the rate of change of generations. The use transplantation of embryo in the practice of dairy cattle breeding ensures the effective implementation of modern reproductive biotechnology, which will promote the expanded reproduction of the most valuable, tested animal complexes.Goal. To study the dynamics of live weight of calves-embryo-transplants and compare them with analogues obtained after artificial insemination, in conditions of farms of different climatic regions of Ukraine.Methods. Zotechnical, statistical, analytical. Analytical part of the work was carried out on the retrospective data of zootechnical records in three farms, in the warehouse of which were introduced repair heifers-embryotransplantants. Biotechnological procedures (in vivo) for embryocollection, transplantation of fresh and frozen-thawed embryos were carried out in accordance with well-known techniques. Materials for system analysis were collected during the period of practical activity of the Laboratory of embryo transplantation at PJSC "Poltavapleservis" and in the period after its reorganization. To study the dynamics of the live weight of repair calves-embryo-transplants in three different climatic and technological conditions farms were selected analogue groups of calves of the corresponding age and breed (in the ALLC "Petrodolynske", the comparison was made with Ukrainian red dairy breeds) born after fertilization artificial insemination of heifers.Results. It was established that the live weight of newborn calves-embryo-transplants of dairy breeds was lower compared to analogues by 6.8% (with fluctuations of 0.86–5.46 kg). Heifers-embryo-transplants yielded to live weight analogues for the entire period of the survey, but had a higher rate of growth. At 9 months of age, the difference in live weight was 4.7%, but the difference in farms of different climatic regions increased significantly: from 0.96 to 8.72%.Conclusions. The tendency of the dependence of the dynamics of the live weight of heifers on the methods of reproduction biotechnology, as well as on the effects of the conditions of retention, is established. Some elements of this trend require further study, in order to optimize the technology of growing a repair stock with high genetic potential. ER -