Birth of calves from vitrified oocytes

After been exposed the interest of oocyte cryopreservation and given the st ate of the art in this field, the authors report new developments. To impro ve the vitrification conditions, volume of vitrification solution in which oocytes are included is lowered and cooling and warming rates are increased to go through the damaging temperature zone as quickly as possible. Using this method called OPS (Open Pulled Straw), calves from both fresh and vitr ified embryos derived from vitrified oocytes were obtained.