Open pulled straw vitrification of goat embryos at various stages of development

This investigation addresses the question whether it is possible to apply the open pulled straw (OPS) vitrification method, found to be effective for cryopreserving caprine (Capra aegagrus horns) blastocysts, to other embryonal stages Morulae. blastocysts and hatched blastocysts were cryopreserved by way of OPS vitrification and blastocysts and hatched blastocysts by conventional freezing Morulae were not included with conventional freezing because in our experience the survival tale is vets' low To assess the viability of the cryopreserved embryos, they were transferred to synchronized does, in most cases, two embryos per doe After OPS vitrification, of rune does receiving morulae, not a single one became pregnant, of 11 does receiving blastocysts. nine (82%) became pregnant (all of which kidded and gave birth to. on average. 1 8 kids), and of nine does receiving hatched blastocysts. three (33%) became pregnant (two of which [22%] kidded, giving birth to a single kid each) After conventional freezing. of 10 does receiving blastocysts, five became pregnant (four of which [40%] carried to term and gave birth to a pair of twins each), and of nine does receiving hatched blastocysts. three (33%) became pregnant (and gave birth to a single kid each) Embryo survival (kids born/embryos transferred) after vitrification for morulae, blastocysts, and hatched blastocysts was 0.70% (16 of 23), and 13% (2 of 16), respectively, and after conventional freezing for blastocysts and hatched blastocysts was 42% (8 of 19) and 19% (3 of 16), respectively The difference in pregnancy and kidding rate between vitrified and conventionally frozen blastocysts was significant. and so was the difference in pregnancy rate between hatched and nonhatched blastocysts, regardless whether OPS-vitrified or conventionally frozen The results of the current study indicate that OPS vitrification is a very effective means of cryopreserving caprine blastocysts Unfortunately, the superiority of OPS vitrification over conventional freezing does not apply to caprine morulae and hatched blastocysts (C) 2010 Elsevier Inc All rights reserved