EFFECTS OF FOLLICLE SIZE AND OOCYTES DIAMETER ON DEVELOPMENTAL COMPETENCE AND IN VITRO EMBRYO PRODUCTION OF AWASSI SHEEP EWES OOCYTES

Abstract

Follicles of different sizes were dissected from ovaries of Awassi ewes and classified  according to size into four groups (A: < 1 mm, B: 1- 2 mm <, C: 2 – 3 mm  < and D: ≥ 3 mm). The resulting oocytes were classified according to their diameter into four groups (A": < 100 mm, B": 100 – 110 mm <, C":110 – 120 mm < and D": ≥ 120mm). Matured oocytes subsequently were subjected to fertilization and culturing was done for six days.  Pearson Chi-square  was used to analyze the data. For the study  the effect of follicular size, significant differences (P < 0.01)  were obvserved in the IVM rate  among the four groups of A, B, C and D (10.67%, 28.97%, 56.25% and 70.83% respectively), significant difference (P < 0.01) was ovbserved in the IVF rate between the two groups C and  D) 26.98% and 61.76% respectively), no significant difference was obvserved in the cleavage rate  between the two groups C and D (33.33 % and 29.41% respectively). The study of the effect of oocytes diameter results showed significant differences  (P < 0.01) in the IVM rate  among the four groups A" ,B", C"and D" (6.16%, 35.59% ,72.30% and 82.02%, respectively), no significant differences were observed in the IVF rates among  the three groups B", C" and D" (22.72%, 38.29% and 42.46% respectively), no significant difference was observed in the cleavage rate between the two groups C" and D" (33.33 % and 41.93% respectively).