Cryopreservation of Bălțată cu Negru Românească cattle immature oocytes by slow freezing method: preliminary research

Abstract

Research on bovine oocytes cryopreservation is important for successful preservation of genetically valuable animal. The transvaginal ultrasound-guided follicular puncture coupled with in vitro embryo production has become competitive and alternative method for MOET (Multiple ovulation and embryo transfer) in dairy cattle. The aim of this preliminary research is to presents the result of Bălțată cu Negru Românească (BNR) cows oocytes recovery by two different protocols and its cryopreservation by slow freezing method. By applying the recovery oocytes from slaughterhouse ovary we obtained an average of 16.34 ± 6.71 oocytes per cow, much higher compared with the Ovum Pick Up (OPU) method, which reveals an average of 2.75 ± 0.2 oocytes per cow. After applying the slow freezing procedures using the ethylene glycol cryoprotectant we observed the oocytes with cumulus cells normal with the spherical shape and normal zone pellucida.