CYTOGENETIC EVALUATION OF IN-VITRO MATURED BOVINE OOCYTES COLLECTED FROM OVARIES OF INDIVIDUAL DONORS

Oocytes were collected after slaughter by aspiration from pairs of ova ries of individual donors. A total of 656 oocytes was selected for IVM from 74 pairs of ovaries (8.9 oocytes per pair, ranging between 1 and 25). The oocytes were matured in droplets of maturation medium (TCM-1 99 medium supplemented with 20% estrous cow serum (ECS), 50 mu g/ml ge ntamycin, 10 mu g/ml FSH, 1 mu g/ml estradiol-17 beta). Cytogenetic an alysis of 348 oocytes showed 79 at the first metaphase (MI; 22.7%, 79/ 348), 11 at the first telophase (TI; 3.2%, 11/348), and 258 at the sec ond metaphase (MII; 74.1% 258/348). Significant differences (P<0.01) w ere shown among the donors regarding the number of oocytes selected fo r IVM and the number of oocytes matured for IVF.