EN
The aim of the experiment was to establish a possibility to obtain foetuses using the in vitro maturition and fertilization of ovine oocytes. The ovine oocytes cultivated for 24 h on enriched TCM-199 medium were inseminated in vitro using a fresh ram’s semen of a concentration of 1 X 10⁷ spermatozoons/ml. Basing on stained smears prepared 16 h since insemination it was found 48.4% of fertilized eggs, 22.6% of degenerated eggs and 29% of eggs in metaphase I and II. Out of 81 oocytes cultivated and fertilized in vitro and then transferred after 16—18 h since insemination into the indirect recipients, 35.8% of degenerated cells and 54.3% of cells in a stage from 2 blastomers to morula and blastocyst was noted after 5 days. After transferring of 21 foetuses in a stage of morula or blastocyst to 6 final recipients gravidity was noted in 5 recipients. Eigth lambs were obtained from 3 recipients. The in vivo survival of foetuses was 53.3%. The obtained results point to a high efficacy of the in vitro cultivation and fertilization of ovine oocytes. Births of lambs point to a full developmental potency of moruls and blastocysts obtained by the in vitro technique.