Efficiency of methods of cultivation of feline embryos depending on the terms of their obtaining after ovarioectomy

Currently, ART is developing rapidly in many animal species. The isolation of OCC from ovarian tissue makes it possible to obtain in vitro embryos for further culturing. Accordingly, culturing embryos in vitro, gives chances to obtain offspring in animals even after their death. Using the gametes of domestic cats as a model, it is possible to improve the technique of obtaining embryos, which can be applied to wild animals of the endangered feline family. The aim of our study was: using cat ovaries after routine ovariohysterectomy, to evaluate the criticality of the temperature regime and time interval during transportation of gonads to the laboratory prior to OCC isolation. The evaluation parameter was the percentage of oocytes at the MII stage, embryos at the morula and blastocyst stage. The method of obtaining OKCs, culturing oocytes and embryos was the same in all groups. The results show that the best values were achieved when the ovaries were received in the laboratory at a temperature of 25 °C and taken for 1 hour to 4 hours, while the increasing the time and decreasing the temperature negatively affects the competence to develop OCC. The study was carried out on the material obtained during scheduled ovariohysterectomy of 12 female cats orchidectomy of 5 male cats. As a result of the work, the technique of transportation of gonads to the laboratory was modified for felines, allowing to obtain a sufficient number of OCCs for subsequent culturing and fertilization in vitro. The technology of collecting feline oocytes and spermatozoa has been developed. The method of IVF and embryo culturing was improved. Based on the conducted research, an algorithm for obtaining quality feline embryos both for further embryotransfer and vitrification is developed.Abbreviations: OCC - oocyte cumulus complex, IVF - in vitro fertilisation, ART - assisted reproductive technologies, OVHE - ovariohysterectomy.