The Effect of Different Ovarian Storage Times and Oocyte Collection Methods on the Quantity, Quality, and Maturation of Buffalo Oocytes In Vitro

This study aimed to ascertain the impact of oocyte harvest methods and storage times on the amount, quality, and rate of buffalo oocyte maturation in vitro. Ovaries were collected from slaughterhouse at four different time storages (0, 3, 6, 9 and 12 h) before processing with three collection techniques slicing, aspiration, and slicing plus the aspiration of oocytes. According to the morphology of cumulus cell layers closely attached to the zona pellucida of the oocytes and the cytoplasmic appearance of the oocytes, the oocytes were divided into 4 groups (A, B, C, and D). Cumulus-oocyte-complexes (COCs) were transferred into in vitro maturation (IVM) medium of TCM- 199 (Sigma) for 24 h. The stages of nuclear maturation were examined by staining the enlarged COCs from each group. The result found that the average quantity of oocytes per ovary ranged from 8.08±1.28 to 9.83 ±1.89 and no significant effect (P0.05) on the quantity of oocytes per ovary. The average of oocytes quality per ovary ranges from 0.2 to 5.00 was a highly significant effect of storage time on quality oocytes (P0.01). The maturation rate in the M-II stage ranges from 1.33 to 3.92 per ovary, and storage time is a significant effect (P0.05) on the maturation rate of local buffalo. The collection methods were highly significant (P0.01) on the quantity of oocytes between slicing and aspiration, also between aspiration plus slicing, and no significant (P0.05) between slicing and aspiration plus slicing. The Average oocyte quality ranged from 0.10 to 4.95 per ovary and the highest in slicing plus aspiration methods (P0.05). The average maturation rate in M-II stage was ranged from 1.00 to 3.85 oocytes per ovary, and the methods of oocytes collection were significant (P0.05) on the maturation rate of local buffalo. In conclusion that the storage time of up to 6 h and aspiration plus slicing is suitable on in vitro maturation of local buffalo.