In Vitro maturation rate of oocytes collected from indigenous cows of Assam after slaughter

Sixty healthy ovaries were collected from local slaughter house. Oocytes from small and medium sized follicles (2–8 mm in diameter) were selected for oocyte collection using aspiration followed by slicing. A and B category (cumulus oocyte complexes (COCs) with more than 5 layers and 3–5 layers respectively of compact cumulus cells surrounding the zona pellucida) were selected for in vitro maturation. A total of 361 oocytes were found to be matured with overall mean maturation rate of 82.59 ± 0.02%. The mean number of grade A, B and C oocytes recovered per ovary was 4.26 ± 0.53, 3.05 ±0.31 and 1.25 ±0.19, respectively. The overall recovery of grade A, Band C oocytes were 256, 183 and 74. Out of 439 oocytes 58.86 ± 0.05%, 33.23 ±0.04% and 9.90 ± 0.04% showed+++, ++and + degrees of cumulus expansion, respectively. It was concluded that aspiration followed by slicing is an ideal method for maximum yield of oocytes and in vitro maturation in indigenous cow of Assam.