[In vitro development of cattle embryo as affected by glucose, serum and EDTA]

The aim of this study was to evaluate the effect of different modifications of sequential synthetic oviductal_fluid [SOF] culture system on developmental competence of in vitro matured/fertilized cattle embryos. Bovine oocytes were matured and fertilized in vitro and then presumptive zygotes were randomly cultured for up to 9 days in different modifications of SOF culture system to consider the effects of glucose, serum and EDTA on embryo development. All the embryo culture systems were efficient to support bovine embryo development till blastocyst stage. There was no significant difference in the ratios of embryos; however, the ratios of blastocyst and also hatchability of embryos cultured in SOF C [51.3%, 43.0% and 83.8%, respectively] were significantly higher than those of all the other SOF groups. Furthermore, while glucose had a partial improving effect on embryo development, a significant decrease in embryo development beyond the morula stage was observed in embryos cultured in SOF system with initial supplementation of EDTA compared with all the other groups. It was concluded that appropriate modifications of SOF culture systems can result in significantly great in vitro embryo development

[Effect of demecolicne treatment on the developmental competency of in vitro matured bovine oocytes]

The aim of this study was to investigate whether demecolicne treatment of matured bovine oocytes adversely affects the process of in vitro fertilization and embryo development. Bovine Cumulus Oocyte Complexes [COC's] were matured in vitro and then were randomly allocated to two treatment groups of common concentrations of demecolicne [0.05 and 0.4 micro g/ml for 30 min] and a control group. COC's were then fertilized and cultured in vitro for up to 9 days when the ratios of in vitro embryo development and the viability of the hatched blastocysts were assessed and compared with the control group [p<0.05]. The ratios of the cleavage and blastocyst formation of demecolicne treated groups [0.4 and 0.05 micro g/ml] were 68.6, 63.5% and 23.3, 32.8%, which were not significantly different from the control group [73.3, 29.0%], respectively. The results of cell-viability were also not significantly different between the control vs. treatment groups. Since the overall indices of in vitro embryo development revealed no significant difference between the demecolicne treated compared to control bovine oocytes, it seems that demecolicne treatment of matured bovine oocytes may not compromise their potency for further in vitro development