Effect of coculture with oviduct epithelial cells on viability after transfer of vitrified in vitro produced goat embryos

This study evaluates the effect of coculture with goat oviduct epithelial cells (GOEC) on the pregnancy rate, embryo survival rate and offspring development after direct transfer of vitrified/thawed caprine in vitro produced (IVP) embryos. Oocytes were recovered from slaughterhouse goat ovaries, matured and inseminated with frozen/thawed capacitated semen, and presumptive zygotes were randomly cultured in synthetic oviduct fluid (SOF) (n = 352) or GOEC (n = 314). The percentage of cleaved embryos reaching the blastocyst stage was 28% and 20% in SOF and GOEC, respectively (P < 0.05). Overall, 26 blastocysts of SOF were transferred freshly in pairs to recipient goats, whereas 58 of SOF and 36 of GOEC were vitrified and transferred directly in pairs to recipient goats after thawing without removal of cryoprotectants or morphological evaluation. The kidding rate was 92% for SOF fresh, 14% for SOF vitrified (P < 0.001) and 56% for GOEC vitrified (P < 0.05); the difference was also significant between vitrified groups (P < 0.01). The embryo survival rate was 62% for SOF fresh, 9% for SOF vitrified (P < 0.001) and 33% for GOEC vitrified (P < 0.05) with a significant difference between vitrified groups (P < 0.01). The results showed that the coculture of IVP goat embryos with GOEC significantly improves the pregnancy and embryo survival rates and leads to the birth of healthy offspring. However, further research using more defined GOEC coculture is required to confirm its capacity to increase the success rate of IVP embryo technology in goat.