Effect of FSH Stimulation of Ovaries on in vitro Maturation of Sahiwal Oocytes Collected by Ovum Pick-up (OPU) Method

Abstract

Background: For conservation of breeds and faster multiplication of superior germplasm in a short period, ovum pick-up- In vitro embryo production (OPU-IVEP) in combination with embryo transfer (ET) can be a viable alternative to the multiple ovulation embryo transfer (MOET). The aim of the present study was to evaluate the effect of FSH stimulation on follicular population, oocyte recovery rate and in vitro maturation of oocytes collected by ovum pick-up in Sahiwal cows. Methods: Sixteen Sahiwal cows aged 3-6 years were randomly divided into two groups. Animals in group 1 (Non-stimulated, n=8) were subjected to ovum pick-up (OPU) twice at 96h interval at random stage of estrous cycle. Animals in group 2 (FSH stimulated, n=8) were subjected to FSH prestimulation (Follitropin-V, 200 mg i/m in 3 tapering doses 100, 60, 40 mg) prior to OPU 1 and with a duration of 96 hrs interval OPU 2 performed. Result: There was significant difference (p less than 0.05) observed between FSH stimulated and non-stimulated group in mean number of follicles available for aspiration (15.31±1.56 and 6.88±0.55, respectively), mean number of oocytes recovered (4.94±0.70 and 3.25±0.40, respectively), cumulus cell expansion rate (92.95 and 83.7% respectively) and 1st polar body extrusion rate (74.64 and 67.44%, respectively). In conclusion, 200 mg of FSH stimulation with decreasing dose prior to OPU increased the follicular population and increased more number of medium and large follicles available for aspiration. FSH pre-treatment also improved the mean number of oocyte recovery and maturation rate compared to non-stimulated group.