Effects of vitrification of partially denuded bovine immature oocytes.

In spite of many trials on bovine oocyte cryopreservation, their efficiency remains unsatisfactory, regardless of method used. Although a births of about 15 calves obtained after transfer of embryos developed from frozen or vitrified oocytes were reported by now, a total efficiency of oocyte cryopreservation, in terms of blastocyst rate obtained, reaches approximately a half of those reported for…