135 Investigation of different in vitro fertilisation media and sex sorting on fertilisation rate of cattle oocytes

The initial purpose of commercial in vitro fertilisation (IVF) is to obtain viable embryos from females who may not be able to produce offspring through conventional techniques. This study was conducted to compare the ability of sex-sorted or non-sorted semen to fertilise matured cattle oocytes in different IVF media in vitro. A total number of 483 oocytes were retrieved from ovaries by aspiration technique, graded, and in vitro matured for 22 h. 60 oocytes were randomly allocated to BO IVF_T BO IVF_C, VitroFert^®, and BO IVF_EGF media for fertilisation with sex-sorted semen and non-sorted semen from the same bull; the experiment was replicated three times. Presumptive zygotes from sex-sorted and non-sorted groups were vortexed for 1 min 10 s to remove cumulus cells and further washed three times in M199 + 10% FBS medium. Denuded presumptive zygotes from both groups were then transferred into a glass slide, stained with Hoechst 33342 stain, and evaluated for pronucleus status with the aid of an inverted microscope. Student’s t-least significant differences were used for mean separation and considered significantly different when α was less than 5%. The high total fertilisation rate was recorded on sex-sorted semen group (VitroFert^® [51.7%], BO IVF_T [43.3%], and BO IVF_C [41.7%]) when compared to non-sorted semen group (BO IVF_T [23.4%], BO IVF_C [13.3%], and BO IVF_EGF [13.3%]); P < 0.05). The current low fertilisation rates recorded in the present study still need modification to achieve acceptable results in future. In conclusion, fertilisation media had no effect on fertilisation rates in both experimental groups, but the sex-sorted semen group recorded a higher total fertilisation rate compared with the non-sorted semen group.

The authors acknowledge the Agricultural Research Council, the Department of Agriculture Land Reform and Rural Development, and the National Research Foundation.