The effect of vitrification device and embryonic stage on survival and developmental competence of gabali rabbit embryos [electronic resource].

Includes references.

The current study aimed to evaluate the effect of vitrification device (straw or cryotop) and embryonic stage (4-8 cell or morula stages) on survivability, normality and in vitro embryo development rate into blastocysts/hatched blastocysts. Total of 24 mature rabbit does of Gabali breed (5-6 months of age, 3-3.5 kg live body weight) were used in this study as embryo donors. Rabbit does were superovulated by PMSG and hCG. Embryos at 4-8 cell stage were recovered by flushing oviducts 32- 43h post-mating, while, embryos at morula stage were recovered by flushing oviducts 64-66 h post-mating. Embryos were vitrified by straw or eryotop. Survival and normality rates were determined. The vitrified embryos were in vitro cultured for 3-5 days to record blastocyst and hatching blastocyst formation rates. Results showed insignificant differences in survival and normality rates of vitrified embryos as affected by embryonic stage, although there were a tendency of higher rates yielded from embryos at morula than at 4- 8 cell stage (87.7 and 89.2% vs. 85.9 and 85.2%, respectively). Survival and normality rates were higher (P<0.05) using cryotop than straw, being 92.1 and 93.1 % using cryotop versus 81.7 and 81.0% using straw, respectively. Expansion and hatching rates were higher (P<0.05) for vitrified embryos at morula than at 4- 8cell stage (80.0 and 71.5% vs. 66.0 and 54.0%, respectively) and using cryotop than straw (81.6 and 75.3 vs. 63.1 and 48.2%, respectively).The current study could be conclude that using the cryotop method to vitrify rabbit embryos rather than straw method at various developmental stages, particulary at morula stage.

Summary in Arabic.

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