Balakrishnan, P PLydia Priscilla, KKAU2019-05-282019-05-282001171861http://krishikosh.egranth.ac.in/handle/1/5810105007PGThe objective of the present study was to analyse the ovarian factors that would influence the type of oocyte recovered for further use in terms of in vitro embryo production. The normal ovaries of crossbred cows collected randomly from the slaughter house were classified into four stages Stage I (SI), Stage Il (S2), Stage III (S3) and Stage IV (S4) of the oestrous cycle according to the visual appearance of CL and ovarian morphology. The length, width, thickness and weight of the ovary were significantly influenced by the stage of the oestrous cycle and the maximum value was recorded during the S3 stage (late luteal phase) of the cycle. The average values recorded irrespective of the stage for length, width, thickness and weight of the ovary was 2.47±O.03cm, 1.81±O.03cm, 1.42±O.03cm and 4.05±O.14g respectively. The mean number of vesicular follicles belonging to the 4 to 8mm category was significantly influenced by the stage of the oestrous cycle (p8mm diameter follicles were not influenced by the stage of the oestrous cycle. The late luteal phase (S3) had more number of follicles in less than 4mm category whereas S3 and S4 stage had more number of follicles in 4 to 8mm and >8mm category. The size of the follicle had an interactive effect along with the quality of oocyte obtained in each category of the follicle. The number of oocytes obtained from <4mm sized follicle was significantly high (pcategories. The good quality oocytes were also found to be significantly higher in number when recovered from <4mm sized follicles. The recovery rate of oocytes as per the stage was found to have a statistical significance (phigher output from ovaries belonging to the S3 phase than the. number obtained from SI, S2 and S4 stage. Moreover, the quality of the oocyte recovered from S3 stage was significantly influenced (pstatistically similar in their effect on oocyte quality. Slicing method yielded the maximum number of oocytes per ovary than when compared to the other techniques employed. There was significant difference in the recovery rate among the methods (pboth in number and quality (6.27 and 61.53 per cent of grade I). The mean number of oocytes recovered by aspiration, puncturing and post aspiration slicing was 4.16, 3.67 and 3.13 respectively. The method of recovery and the quality of oocyte recovered had an interactive and significant effect on the oocyte recovery rate (pThe level of sodium, potassium, iron and copper in the follicles of various diameters present during the different stages of the cycle in the ovaries was found to vary significantly between stages. The level of zinc was not influenced by the stages of the cycle. The variation in the concentration of the minerals was found to be related with the normal physiological changes that occurred during the different stages of the cycle.ennullThesis