Effect of Two Heterologous Sera on Meiotic and Fertilization Capacity of the Ovine Oocytes In Vitro

The aim of this study was to investigate the effece of mare serum and fetal bovine serum (FBS) on meiotic and fertilization capacity of sheep oocytes in vitro Cumulus Oocyte Complexes (COCs) were recovered from ovaries using slicing method. COC’s were washed three time in maturation medium without any serum supplementation. The COC’s were randomly divided into three groups. Group 1 (n = 170) COC’s were fresh control and cultured in maturation medium without serum supplementation. Group 2 (n = 169) COC’s were cultured in maturation medium supplemented with 10% mare serum. Group 3 (n = 167) COC’s were cultured in maturation medium supplemented with 10% FBS. Cumulus expansion was the index of oocyte maturation. To fertilize the mature oocytes، 24 h after maturation oocytes were transferred to the fertilization medium and then sperm was added to the fertilization medium. Twenty four hours post-fertilization، oocytes were denuded mechanically by gentle pipeting، fixed in a mixture of acetic acid and alcohol، stained for 10 min with 1% (w/v) orcein in 45% acetic acid and examined for their fertilization potential. The rate of oocyte maturation in groups 1، 2 and 3 were 59/82%، 77/55% and 89/27%، respectively. The rate of fertilization in three groups was 19/19%، 39/64% and 50%، respectively. Significant difference was observed between three groups (p < 0. 05). The results showed that the medium contain 10% percent fetal bovine have higher in vitro maturation and fertilization of oocyte rates than mare serum and the control groups