Effects of recombinant human follicle stimulating hormone on follicle development and ovulation in the mare.

The study investigates the impact of recombinant human follicle stimulating hormone (rhFSH) on follicle growth, ovulation, and embryo production in mares, comparing it to the previously used equine pituitary extract (EPE). The results suggest that rhFSH at the studied doses doesn’t significantly affect these aspects in mares.

Objective of the Research

• The purpose of the study was to explore the effects of the gonadotrophin preparation, recombinant human follicle stimulating hormone (rhFSH), on the development of follicles, ovulation, and production of embryos in mares.

Methodology

• Five mares were treated twice daily with 450 i.u. of rhFSH starting from the 6th day after ovulation, while a control group of five mares were treated with saline in place of rhFSH.
• The response was monitored by conducting daily scans of the mares’ ovaries and evaluating systemic oestradiol-17beta and progesterone concentrations.
• Ovulation was induced when the dominant follicle(s) exceeded 35mm, and embryos were collected on the 7th day after ovulation.
• After an untreated oestrous cycle to eliminate rhFSH effects, the groups were interchanged and treated twice daily with 900 i.u. rhFSH or saline.

Results

• It was discovered that neither dose of rhFSH influenced the number of days before the dominant follicle(s) grew to 35 mm, the quantity of follicles of various sizes at ovulation induction, or the pre- or post-ovulatory oestradiol-17beta or progesterone concentrations.
• The number of ovulations or the output of embryos were also not impacted by the rhFSH treatment.
• In conclusion, the research indicates that rhFSH, at the administered doses, is not effective in stimulating multiple follicle development in mares.