Full-term Development of in vitro Produced-Vitrified Water Buffalo (Bubalus bubalis Linn) Embryos

Assisted reproductive technologies such as artificial insemination (AI) and multiple ovulation and embryo transfer (MOET) have been introduced to overcome reproductive inefficiencies and accelerate genetic gain. However, MOET in water buffalo is compromised by the poor ovulatory response of this animal species to hormonal treatment (Karaivanov 1986; Karaivanov et al. 1990; Misra et al. 1990; Cruz et al. 1991). In vitro production of embryo provides an excellent source of embryos for basic research on developmental biology and physiology and for the application of emerging biotechnologies such as nuclear transfer and transgenesis. Our initial report have shown the efficiency of this technique as alternative tool for Full-term developments of in vitro produced (IVP) vitrified water buffalo embryos derived from in vitro matured and fertilized oocytes were assessed. Oocytes were matured in vitro for 2224 hours and fertilized by sperm-oocyte co-cultured in a humidified incubator for 6 to 8 hours. Presumptive zygotes were co-cultured with cumulus cell monolayers for development. Resultant pre-implantation stage embryos within 7 days of in vitro culture were cryopreserved through vitrification method and post-warming, these were transferred non-surgically to recipients. Out of the 149 IVP vitrified embryos transferred to 79 recipients, a 13.9% (11/79) calving rate was achieved marking a 7.9% (11/149) full-term development of IVP vitrified embryos. Eleven healthy normal calves with average birth weights of 37.0±5.4 kg were born. These results demonstrate the viability of IVP vitrified water buffalo embryos, potential application of the techniques in optimizing the female contribution on genetic progress, and on overall water buffalo genetic improvement.