COMPARATIVE SEASONAL ASSESSMENT ON THE QUALITY OF BLACK BENGAL GOAT OOCYTES IN VIEW OF IN VITRO EMBRYO PRODUCTION

Abstract

In vitro maturation (IVM) of oocytes provide an excellent opportunity for cheap and abundant embryos for carrying out animal improvement. With the aim to study the oocyte quality in different seasons of Black Bengal goat, both right and left ovaries were collected from the slaughter houses. For each of the specimens, gross parameters such as right, left, corpus luteum (CL)-present and -absent group and evaluated on the basis of weight (g), length (cm), width (cm), follicles aspirated and number and state of cumulus-oocyte-complexes (COCs), normal COCs and abnormal COCs, the effect of season on cumulus oocyte complexes (COCs) of goat oocytes. Our study revealed that the average number of follicles in both left and right ovaries were higher in summer (12.50; 10.48) than in winter season (8.08; 8.21). Both right and left ovaries are great source for large number of oocyte and without-CL ovaries are considered as suitable source to supply quality oocyte for in vitro embryo production of goat. In different corpus luteum-present ovaries total number of follicles were distinctly higher in summer season (9.00±1.00) compared to that of winter season (6.50±1.84). In different corpus luteum-absent ovaries total number of follicles were distinctly higher in summer and winter season (13.52; 11.84) compared to that of CL present ovary in summer and winter season (9.00; 6.50). The oocyte recovery rate (2.14) was higher in summer than in (1.97) winter season. The results obtained in the present study showed that recovery rate of grade A and B oocytes were higher in summer than that of in winter and recovery rate of grade C and D were higher in winter than that of in summer. In the present study a significantly greater number of oocytes per ovary were recovered from ovaries without a corpus luteum (2.23; 2.02) than from ovaries with a corpus luteum(1.50; 1.50). Greater number of oocytes per ovary were recovered from ovaries with and without a corpus luteum (1.50; 2.23) in summer than from ovaries with and without a corpus luteum (1.50; 2.02) in winter. So the summer was the best season for recovery of COCs which have a worthy competence to be matured in vitro.