Cryopreservation of bovine embryos at different stages of development by vitrification

Abstract EN

To compare the survival rate of bovine embryos cryopreserved by vitrification at various stages of development, embryos were vitrified using an ethylene glycol based solution.

The survival of the embryos after thawing was assessed by their morphology and their ability to develop to next stages.

Results revealed that 100% of normal embryos were morphologically recovered at morula, compact morula and blastocyst stages after thawing.

While, only 40 and 62% of embryos were recovered at 4-cell and 8-cell stages, respectively.

No viable embryo at 4-cell stage was found for 24 h in vitro culture after thawing.

A percentage of 80% of embryos was viable for 48 h in vitro culture after thawing.

Viability rates for embryos at morula and compact morula and blastocyst stages were 100% after 24 or 48 h of in vitro culture.

Percentage of embryos developed to next stage was higher (P<0.05) for embryos at morula and compact morula (100%) than those at blastocyst (83%) and 8-cell stages (25%).

While, embryos at 4-cell stage recovered had no ability to develop to next embryonic stage, being the lowest (0%) after 24 h in vitro culture.

In conclusion, using cryopreservation embryos is possible to adjust the synchronous recipients, particularly at morula and compact morula stages.