Consequences Of Vitrification On Survivability And Subsequent Development Of Shami Goat’s Early Embryos In Different Cryopreservation Protocols

Abstract

Due to the necessity to preserve the in vitro produced embryos of pure breeds such as Shami goat, vitrification of early embryos contributes to the preservation process significantly. In the current study, the effectiveness of vitrification on Shami goat early embryos was evaluated according to the concentration of cryoprotectant and equilibrium time. A total of 850 embryos (2-4 cell stage) were randomly distributed into 6 groups (treatments): A1, A2 and A3 groups were vitrified in a cocktail of dimethyl sulfoxide (13% v/v), ethylene glycol (13% v/v) and sucrose (2M) across three equilibrium times (A1: 8 minutes, A2: 10 minutes and A3:12 minutes). B1, B2 and B3 treatments were vitrified in a cocktail of dimethyl sulfoxide (15% v/v), ethylene glycol (15% v/v) and sucrose (3 M) across three equilibrium times (B1: 8 minutes, B2: 10 minutes and B3:12 minutes). Results showed that the frozen - thawed embryos in B2 treatment achieved the best rates of survivability ( 93.29%; p <0.01) , cleavage ( 73.15%; p <0.01), degeneration (6.71%, p <0.01), blastocyst (53.21%, p = 0.01), arrest (7.33%, p <0.01) and hatched blastocyst (37.93%, p = 0.03). No significant differences were noticed in morula, early and expanded blastocyst stages. It is concluded from the current study that vitrifying the blastomeres of Shami goats in a cocktail containing dimethyl sulfoxide (15% v/v), ethylene glycol (15% v/v) and sucrose (3 M) at an equilibration time of 10 minutes contributes to obtaining the highest survival rates after freezing and the highest possible rates of blastocysts.