A comparative study of oocyte between native cattle and buffalo species in Bangladesh: a qualitative and quantitative approach

In vitro embryo production (IVP) can help alleviating reproductive difficulties in cattle and buffalo. This study compared qualitative and quantitative features of native cattle and buffalo ovaries and oocytes to understand them comprehensively. In addition, it was conducted to pick the ideal ovaries for oocyte collection and to assess either maturation affects oocyte diameter or not. The ovaries were collected from the local slaughterhouses of Dhaka city, Bangladesh. Next, the quantitative parameters of ovaries were measured, the follicular fluid was aspired, the oocytes were classified, and the diameters of oocytes were determined in both pre and postmaturation. Here, the results revealed that the ovaries of cattle and buffalo differed significantly (p < 0.05) in weight, length, width, and depth regardless of the ovary's position and the corpus luteum (CL) condition. The numbers of normal and abnormal oocytes per ovary were 1.19 and 0.96 in cattle and 1.50 and 1.13 in buffalo, respectively. Moreover, a significant difference (p < 0.05) was observed between the oocytes' diameter in cattle and buffalo (cattle 85.64 ± 8.16 μm vs. buffalo 99.92 ± 8.65 μm) and before and after the maturation of oocytes within the same species. It may be concluded that the buffalo ovary was greater in size, and the oocyte was larger than the cattle ovary and oocyte. Any ovaries-irrespective of the ovary's position and the CL status-can be a good source of potential oocytes. Besides, the maturation process may ultimately affect oocytes' diameter increase.