IMPACT OF DIFFERENT CRYOPROTECTANTS OR THEIR COMBINATIONS ON VITRIFIED BOVINE OOCYTES MORPHOLOGY

The present study was conducted to investigate the impact of different cryoprotectant like Ethylene glycol (EG), Propanediol (PROH) and Dimethyl sulfoxide (DMSO) alone or their combinations on morphology of bovine oocytes using vitrification. The vitrification of bovine oocytes was performed using 10, 20 and 40% concentration of EG and 10, 20 and 40% DMSO, 2.5, 5 and 10% PROH alone or combinations of 20%EG + 20%DMSO, 5% PROH + 20% DMSO, 5% PROH + 20% EG or 5% PROH + 20% EG +20% DMSO. The results showed that combinations of the different cryoprotectant proved to be more efficient than
using Propanediol (PROH) or Dimethyl sulfoxide (DMSO) alone except Ethylene glycol (EG). The morphological damages of bovine oocytes were found less (9.8%) using combination of 20% EG + 20% DMSO (34.14%) compared with 5% PROH or 20% DMSO to be (27.27%). A combination of 20% EG and 20% DMSO resulted in the highest percentage of the normal morphologically oocytes (82.81%) compared with 65.5 and 72.73% with 5% PROH and 20% DMSO, respectively. Furthermore, the combinations of PROH and DMSO when used alone were found to induce adverse effects on the morphology of bovine oocytes. However, it can be concluded that combinations of 20% EG + 20% DMSO were found better to maintain the integrity and internal structure of bovine oocytes by vitrification.