Sri Wahjuningsih

Effect of Follicle Size on Metaphase II and Cleavage Rate of Goat Oocyte

The aim of this research was to determine the effect of follicle size on Metaphase II and cleavage rate of goat Oocyte. Ovaries from slaughterhouse transported to the laboratory within 2 h of slaugtering in normal saline. The ovaries were cut and classified two classes of follicle size : small (2-4 mm diameter ) and large (>4-8 mm diameter) follicles. All culture were done in ten replicates at 38.5 o C, 5 % CO2, 95 % humidity. Only fully Cumulus Oocyte Complexes (COCs) and homogenous cytoplasm were used. The COCs were matured for 26 h in TCM-199 medium supplemented with FCS 10 % + EBS 10%. Chi square test were used for statistical analysis. Metaphase II rate was determined by microscope in a sample of COCs denuded, fixed and stained with acetoorcein 1 %. In vitro fertilization was performed using frozen semen (2 X 10 6 spermatozoa/mL in EBSS solution. The percentage of COCs reaching Metaphase II was 86.42 % (261/302) and 74.33 % (220/300) for oocytes originating from large and small diameter follicles,respectively (P<0.05). After in vitro fertilization , the developmental competence of oocytes dependently increased with follicular size. Higher cleavage rate was obtained from large follicles compare to small follicles (P<0.05).