TRANSFER OF VITRIFIED EMBRYOS OF PIGS

Currently, embryo cryopreservation is a commonly used technique of emb ryo transfer in the main species of farm animals. Trials with embryo c ryopreservation in pigs have not been successful before now. Nagashima et al. (1994) presented a survey reporting on the birth of 14 piglets in total in various trials. Cryopreservation of pig embryos have been very difficult. The method of vitrification - method of mammalian emb ryo cryopreservation without ice crystals being formed - seems to be c onvenient for cryopreservation of mammalian embryos. About five days o ld embryos in the stage of perihatching blastocysts were used for pres ervation. The preserved embryos were used for laparoscopic transfer to three recipients that received 13, 15 and 15 thawn embryos, respectiv ely. The transfer was not successful; the recipients returned to estru s in 22, 22 and 23 days, respectively. It is therefore difficult to sa y whether the case was embryonic mortality in the last recipient. Grou p 2 comprised five recipients in total (2 uninseminated and 3 insemina ted ones). Following the transfer of 13 to 16 embryos, conception was observed in one uninseminated recipient (abortion at the end of the 2n d month of gravidity) and one inseminated recipient. Both recipients b ecame pregnant after embryo transfer by vitrification technique descri bed in the paper by Riha (1993). The inseminated pregnant recipient de livered seven piglets, six of them were live-born; three piglets are p henotypically different, born from cryopreserved embryos. This trial e nabled us to be among a few stations where cryopreservation of porcine embryos has been successful.