Evaluation of Bovine Ovaries, Follicles and Cumulusoocyte-Complexes (CoCS) in view of in vitro production of Embryo

• Main Author: Nur Farah Atiqah Yahya
• Format: Academic Exercise
• Language: English
• Published: 2016
• Subjects: S Agriculture (General)
• Online Access: https://eprints.ums.edu.my/id/eprint/18009/1/Evaluation%20of%20Bovine%20Ovaries.pdf; https://eprints.ums.edu.my/id/eprint/18009/
• Institution: Universiti Malaysia Sabah

The present study was conducted at the Anatomy and Physiology laboratory, Faculty of Sustainable Agriculture, Universiti Malaysia Sabah Sandakan Campus from July 2015 until September 2015 to undergo the evaluation of bovine ovaries, follicles and cumulus-oocyte-complexes (COCS) in view of in vitro production of embryo. The objectives of this study were to perform the evaluation of bovine slaughterhouse ovary, follicles, and cumulus-oocyte-complexes (COCS) and to compare the effect of collection techniques on the recovery rate of COCS. The collected slaughterhouse ovaries was classified as corpus luteum present (Cl +) and corpus luteum absent (Cl-) groups. It was found that 62.5% of the ovaries collected were Cl- type and only 37.5% were Cl+. Observation on follicular number on ovarian surface was done in both types of ovaries. The higher number of visible follicles was found in ovaries without corpus luteum (15.5±2.7 and 45.0±14.3) compared to ovaries with corpus luteum (11.0±2.0 and 35.8±14.5). Two COCs collection techniques were applied which were blunt dissection and aspiration techniques. For the blunt dissection, individual follicles were dissected from the ovaries by using scissors and forceps and the follicular materials were harvested individually in the Petri dish. For the aspiration, the follicles were aspirated by 10 ml syringe attached with 18 gauze needle. The aspirated follicular materials were transferred slowly into a falcon tube, precipitated for 10 minutes, then the upper part was discarded and in the lower part a small amount of 0.9% physiological saline solution with 5% BSA was added and entered into a Petri dish. The follicular materials collected from both techniques were observed under microscope to categorize the coes as grade A (oocyte homogenously surrounded with cumulus cells), grade B (oocyte partially surrounded with cumulus cells), grade C (oocyte not surrounded at all with cumulus cells) and grade 0 (degeneration observed both in oocyte and cumulus cells). Grade A and grade B were considered as normal COCs and grade C and grade D were considered as abnormal COCs. The results were analysed using mean ± SE with the help of Microsoft Office Excel 2007. Comparatively higher number of follicles aspirated and dissected from ovaries without Cl (11.2±1.8 and 37.8±14.9) than from ovaries with Cl (10.5±1.S and 28.3±15.6). The result further indicated that ovaries without Cl contributing more number of total coes collected per ovary (6.8±1.0) and more normal (A and B grades) coes (5.7±0.9) than that of ovaries with Cl (6.0±2.0 and 4.5±1.S, respectively) in blunt dissection technique and reverse trend was found in aspiration technique. Ovaries without CL were suggested to be suitable for collecting COCS for in vitro production of bovine embryos although the reverse trend was found in aspiration technique. Blunt dissection is found more efficient than that of aspiration technique on the harvesting of high number of COCS with recovery rate of 61.6% and 16.5%, respectively. There was also more efficient in the recovery rate of normal(A and B grades) COCs by blunt dissection technique (48.6%) than by aspiration technique (11.7%). The result of this experiment is a preliminary work for planning and execution of future pragmatic research on in vitro production of bovine embryos.