PRODUCTION OF FINAL BEEF HYBRIDS IN CATTLE BY TRANSFERRING FROZEN EMBRYOS PRODUCED BY IN-VITRO METHOD OF MATURATION, FERTILIZATION, AND CULTIVATION

A cryopreservation procedure for embryos produced by IVM-IVF-IVC metho d was tested and conception rate in recipients of transferred preserve d IVM-IVF-IVC embryos was evaluated in the presented paper. Ovarian oo cytes were recovered from ovaries of slaughtered heifers. Oocyte matur ation (19-22 h) was followed by incubation with capacitated sperm cell s of the selected sire. Fertilization and cultivation were realized on cumular cell monolayer till 7th day past fertilization. Routine metho ds were used for embryo freezing and thawing. Any significant differen ces were not found in the conception rate as related to recipient type (cow x heifer), individual herds, and quantity of transferred embryos (P > 0.05). In total, 306 ET were realized, 102 recipients conceived (33.3%). Statistically significant tendency (P < 0.01) was found betwe en conception rate and stage of the embryo. Effects of the embryo batc h and the sire's breed type on recipient conception rate were also hig hly significant - P < 0.01 and P < 0.05, respectively.