Effect of follicle stimulating hormone stimulation on in-vitro oocyte maturation in Sahiwal cattle

Abstract

The current investigation took place at the College of Veterinary Science, Korutla, Telangana, within the framework of the Embryo Transfer & In-Vitro Fertilization (ET & IVF) project. The objective was to assess the impact of Follicle Stimulating Hormone (FSH) stimulation on ovarian follicular growth, oocyte yield, oocyte quality, and In-Vitro maturation (IVM) of oocytes. In this study, irrespective of the estrous cycle, 20 non-lactating Sahiwal cows were evenly divided into two groups. Group 1 animals (non-stimulated, n = 10) underwent ovum pick-up (OPU) once at a random stage of the estrous cycle. In Group 2 animals (FSH-Stimulated, n = 10), at a random stage of the estrous cycle (Day 0), a progesterone (P4)-releasing intravaginal device (CIDR) was inserted, and from day 4 onwards, they were treated with injection FSH (200mg) intramuscularly in 8 tapering doses with 12-hour intervals. After a 36-hour coasting period, CIDR was removed, and oocytes were recovered by OPU. The retrieved oocytes were incubated for 24 hours for in-vitro Maturation. After 24 hours of IVM, the oocytes were assessed for maturation. Follicle Stimulating Hormone treatment (p<0.05) resulted in an increase in the total number of follicles (non-stimulated, 7.30 ± 0.36 vs. FSH-stimulated, 21.50 ± 1.67), the number of medium follicles (4 - 8 mm; non-stimulated, 2.00 ± 0.25 vs. FSH-treated, 11.4 ± 1.04), large follicles (non-stimulated, 0.7 ± 0.15 vs. FSH-stimulated, 7.90 ± 1.15), total number of oocytes recovered per animal (non-stimulated, 6.10 ± 0.27 vs FSH-stimulated, 13.70 ± 1.19), and an increase in the number of good quality oocytes. The study concluded that FSH stimulation was effective in stimulating the growth of the follicular population prior to OPU and enhancing In-Vitro oocyte competence for in-vitro embryo production in non-lactating Sahiwal cows.