Abstract

The frequency of live ovum pick-up (LOPU) is one of the main factors affecting buffalo oocyte collection. This study discussed the effect of LOPU frequency on buffalo oocyte collection in purpose of improving the efficiency of water buffalo embryo in vitro production and laying a foundation for the establishment of a high efficient system. 92 buffalo buffaloes from Guangxi Buffalo Research Institute (including Murrah, Nili-Ravi buffalo and hybrid buffaloes), aged 4-12 years, weighing 580-700kg, were used for LOPU for 5 consecutive times at a frequency of every 3 days. The donors were not treated with hormone and the oocytes collected were divided into A, B, C and D grades. All data(the number of visual oocytes ,punctured follicles, collected oocytes, available oocytes, recovery rate, availability rate, follicles, punctured follicles, recovered oocytes, etc.) was collected and counted to obtain the average number of oocytes in LOPU and the rate of high quality oocytes were evaluated. The number of admissible follicles, puncture follicle, collected oocytes were expressed by mean ±standard error (S.E.M). The statistical software SPSS 17.0 was used to analyse the variance. The results showed that the average percentage of high quality oocytes (A and B grade) was 66.05%. When conducting continuous LOPU, the rate of high quality oocytes (grade A) from the first batch to the fifth batch were 58.95%, 64.05% and 70.28%, 69.07% and 67.86%, respectively, while the recoveries rate were 43.07%, 35.43% 4.60%, 37.42% and 37.46%respectively,both showed no significant difference between each batch (P >0.05).However, the rate of grade C oocytes (naked eggs and reticular cells) during 5 times were 39.99%, 24.65%, 15.95%, 23.81% and 21.17%, respectively, showed a significant difference (P<0.0001), and with a decreasing trend as the frequency of LOPU increases. This study laid a foundation for further improving of the efficiency of buffalo LOPU.

Keywords:Buffalo; LOPU frequency; Oocyte quality