Effect of ovary preservation period on recovery rate and categories of dromedary camel oocytes

AbstractThe aim of this study was to evaluate the effect of different periods of ovary preservation at 25–30°C for 5, 6, 7, 9, 12 and 24h on recovery rate and oocyte categories of dromedary camel oocytes. Camel ovaries were collected from El-Bassatein slaughterhouse, Cairo. The collected ovaries were placed immediately after slaughtering into thermos in saline solution (0.9% NaCl) supplemented with antibiotics (100IU penicillin and 100μg streptomycin/ml) at 25–30°C and transported to the laboratory within 4–5h. Ovaries were washed three times with warmed (30°C) phosphate buffer solution (PBS) and one time with ethanol (70%). All visible follicles on the ovarian surface (2–8mm in diameter) were counted. Oocytes were aspirated using a 20-gauge hypodermic needle. Oocyte yield was recorded and the number of oocytes/ovary was calculated. Oocytes were classified into five categories (compact, partial denuded, denuded, shrunken and cleaved oocytes). Results show that average number of follicles on each ovary was not significantly affected by preservation period, although tended to reduce only after 5h of ovary preservation. However, this number was insignificantly reduced by increasing period of ovary preservation more than 5 up to 24h. Average number of oocytes on each ovary was significantly (P<0.05) reduced only between 5 and 6h of ovary preservation. Average number of oocytes showed higher reduction rate between 5 and 6h from 12.4 to 9.3/ovary as well as between 9 and 12h. Oocyte recovery rate showed insignificant decrease from 88.1% at 5h to 78.6% at 9h of preservation. However, it showed significant (P<0.05) reduction to 62.0% between 9 and 12h, then insignificantly decreased to 58.6 at 24h of preservation of the ovaries. Frequency distribution and recovery rate of each category was the highest for compact oocytes and the lowest for cleaved oocytes at all periods of preservation. Increasing preservation period significantly (P