Full-term potential of goat in vitro produced embryos after different cryopreservation methods

Cryopreservation of preimplantation embryos represents a major challenge due to their shape and relatively large cells. Embryo source and cryopreservation method are key factors to cryotolerance efficiency and few reports have investigated more promising protocols for goat embryos. The study was aimed to compare different cryopreservation methods for goat in vitro produced (IVP) embryos. Goat blastocysts were subjected to conventional freezing (CF), Dimethyl sulfoxide vitrification (DMSO-V) and Dimethylformamide vitrification (DMF-V). Cryopreserved blastocysts were assessed for re-expansion, cell viability and in vivo development rates. Blastocyst re-expansion after cryopreservation was similar between groups, but cell viability was lower for DMF-V (32%) than CF (68%) and DMSO-V (60%). Pregnancy and delivery rates were similar for CF (60% and 50%) and DMSO-V (50% and 45%) and higher then DMF-V (20% and 15%), respectively. Finally, kidding rates were also indistinguishable for CF (40%) and DMSO-V (35%), but higher then DMF-V (12.5%). In conclusion, conventional freezing and vitrification using DMSO have similar efficiencies for cryopreservation of goat IVP embryos and cryoprotectant for vitrification affects its outcome.