Vitrification of in vitro-produced bovine embryos matured inmodified TCM-199 medium


Abstract: In vitro-produced bovine embryos matured in modified Tissue Culture Medium 199 (TCM-199) were vitrified at the 7th and 8th days of culture, and development at 48 h after warming was recorded. Ovaries were obtained from a local abattoir, and the oocytes were recovered by slicing method and divided into two main groups. The first group included cysteamine in the TCM-199 (Group A) and the second did not (Group B). They were incubated for 24 h at 38.8 °C in an atmosphere of 5% CO2 in humidified air. Matured oocytes were fertilized with 1-2 × 106/mL of frozen-thawed bull semen. At the end of the period the embryos were divided into two subgroups in order to be developed. Therefore, four groups were established: Group AI-SOF (synthetic oviduct fluid), Group AII-CR1aa (Charles Rosencrans), Group BI-SOF, and Group BII-CR1aa. The rates of blastocyst development and expanded blastocysts were detected as 20%, 18.1%, 24.6%, and 22.5% and survival rate as 5.5%, 23.6%, 0%, and 5.2%, respectively, showing statistically significant superiority in Group AII-CR1aa at the level of P < 0.05. In conclusion, supplementing cysteamine into maturation media with subsequent culture in AII-CR1aa had a positive effect on blastocyst survival after vitrification.

Keywords: Bovine, embryo, cysteamine, maturation, vitrification

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