الفهرس | Only 14 pages are availabe for public view |
Abstract This study was carried out at the International Livestock Management Training Center (ILMTC), belonging to the Animal Production Research Institute, Agriculture Research Center, Ministry of Agriculture, in cooperation with Department of Animal Production, Faculty of Agriculture, Damietta University. The aim of this study was to investigate the effect of corpus luteum (CLs), follicular size on grade and in vitro maturation of bovine oocytes, in relation with and follicular fluid composition. Ovaries were obtained from abattoirs and classified according to bearing CLs(CL+)or non-bearing CLs(CL-),all visible follicles were measured according to their diameters into small follicles (SF≤8 mm) and large follicles (LF>8 mm).The follicular fluids (FF) and oocytes were aspirated from SF and LF in CL+ and CL-ovaries. Oocytes were classified into good, fair and poor quality. Only good quality oocytes were in vitro matured in TCM-199 medium. The concentration of estradiol-17β (E2), progesterone (P4), testosterone and lactic acid in FF were estimated. The main results could be summarized as the following: 1. A total of 2766 follicles and3976 oocytes were collected from 827 bovine ovaries with an average of 6.62 follicles / ovary and 4.65 oocytes/ovary, respectively, regardless the ovarian status (with CL+ and without CL-). Ovaries with CL+ (355) yielded 1290 oocytes, by the aspiration method, (1.8/ovary) while ovaries without CL- (472) yielded more oocytes (2686) (2.85/ovary). Also, CL+ ovaries showed significantly (P<0.05) lower oocyte recovery rate as compared to CL- ovaries. 2. The number of large follicles and oocytes per ovary was significantly (P<0.05) higher than the number of small follicles and oocytes per ovary. |