In this study in which the effects of maturation and fertilization media supplements and co-culturing on in vitro production of sheep embryos were investigated, primary oocytes (n=454) collected from ovaries of slaughtered ewes were used. Oocytes divided randomly into 4 groups were matured for 26 h in TCM 199 medium with different supplements:
Group I (SH): TCM 199 medium supplemented by 20% sheep estrous serum, 10 ug/ml FSH, 10 ug/ml LH and 1 ug/ml estradiol 17fi,
Group 2 (S): TCM 199 medium supplemented by 20% sheep estrous serum.
Group 3 (H): TCM 199 medium supplemented by 10 ug/ml FSH, 10 ug/ml LH and 1 pg/ml estradiol
170, and
Group 4 (M): TCM 199 medium without serum and hormones.
After maturation, oocytes which were again divided into 3 subgroups were transferred in SOF medium supplemented by 2% (D), 5% (O) and 10% (Y) sheep estrous serum and fertilized in vitro for 18 h with fresh ram semen collected by electro-ejaculation and washed. After fertilization, oocytes were divided into 2 subgroups [Group 1 (KK): Co-culture with sheep oviductal epithelial cells; Group 2 (K): Culture without sheep oviductal epithelial cells] and cultured for 7 days. At the end of this period embryos were evaluated for their developments.
The highest cleavage and morula rates were obtained in SH+Y+KK group (62.5% and 43.8%, respectively) and the lowest rates (8.7% and 4.3%, respectively) in M+D+K group in this study.
According to the results, we concluded that supplementation of in vitro maturation media with 20% sheep estrous serum and hormones, in vitro fertilization media with 10% sheep estrous serum and co-culturing with sheep oviductal epithelial cells after fertilization could improve the cleavage and morula rates.