Quality of Oocytes Obtainded from Abattoir-Derived Ovaries Kept at 37oC and 5oC

Oocyte quality is a determinant of successful in vitro oocyte maturation. This study was conducted to determine quality of oocytes obtained from ovaries of cows slaughtered at Ubakala abattoir, Umuahia, South East Nigeria and stored at 37oC and 5oC from time of ovary collection at the abattoir to the time of processing in the laboratory. Oocytes’ aspiration was done according to standard technique. The aspirated oocytes were qualified following a standard grading system (I-IV). Ten ovaries were processed for both storage systems. The number of Grade 1 oocytes in the ovary kept at 37oC was 6 while that kept at 5oC was 9. With grade II oocytes, an equal number of seven oocytes were recorded for the two storage systems. The number of Grade III oocytes obtained in ovaries stored at 37oC and 5oC were 23 and 30, respectively. However, there was no significant difference (P>0.05) in the number of oocytes of various grades obtained from ovaries kept at 37oC and 5oC immediately after animal slaughtered to the time of aspiration in the laboratory. On the aggregate, a greater number of oocytes were obtained from ovaries kept at 5oC than those kept at 37oC, though more quality oocytes (I and II) were obtained with 37oC. Generally, the study showed low number of oocytes obtained from the two systems primarily due to malnourishment and old age of the cows slaughtered in the abattoir. Having yielded relatively more quality and cultivable oocytes, storage at 37oC is preferred to storage at 5oC.