Comparative evaluation of the quality of oocytes retrieved from bovine ovaries by different oocyte retrieval methods from selected slaughter house in Kampala

Abstract

The study was thought to evaluate quantity and quality of oocytes from bovine ova retrieved by different methods from selected slaughter house in Kampala. Three oocyte retrieval methods that was aspiration, ovary slicing and aspiration plus slicing were used to retrieve oocytes from the follicles of ovaries which were counted upon retrieval and graded as Good (oocytes that had many complete layers of cumulus cells (≥3) and uniform cytoplasm), Fair (oocytes that had thin or incomplete layers of cumulus cells (≤2) and uniform cytoplasm) and Poor (oocytes that had few or no cumulus cells). Aspiration plus slicing and ovary slicing oocyte retrieval techniques yielded with the highest number of oocytes (15.29) and (14.86) respectively compared to aspiration (12.57). Ovary slicing yielded with the highest number of culture grade oocytes (Good) (8.36) and aspiration yielded with the highest number of oocytes under poor (5.29). Aspiration plus slicing and ovary slicing yielded with the highest number of oocytes and this was attributed to the ability of the methods to retrieve oocytes from both the surface follicles and deeper cortex, ovary slicing yielded with the highest number of culture grade oocytes and this was attributed to the nature of the method were oocytes were not subjected to stress during the process of collection and aspiration yielded with the highest number of poor grade oocytes and this was attributed to the stress subjected to the oocytes passing them into the needle to the syringe during the retrieval process which might have resulted into loss of the cell layers. The results from this report may open a way for use of aspiration plus slicing and ovary slicing as the recommended methods for oocyte retrieval for maximum yield of quality oocytes in bovine ovaries, more research is needed to see if the retrieval techniques provide the same results using ovaries from other animals.