Enhancing Fertility in Mares: Recombinant Equine Gonadotropins.
Authors: Roser Janet F, Meyers-Brown Geraldine
Journal: Journal of equine veterinary science
Summary
Reproductive technologies such as embryo transfer and intracytoplasmic sperm injection demand multiple oocytes to maximise success rates, making reliable superovulation protocols essential for breeding programmes involving subfertile mares or stallions. Roser and Meyers-Brown reviewed evidence supporting recombinant equine gonadotropins—specifically recombinant FSH (reFSH) and recombinant LH (reLH)—as superior alternatives to historically variable hormone treatments such as equine chorionic gonadotropin, porcine FSH, and pituitary extracts. Recombinant gonadotropins offer distinct advantages: they can be produced in consistent, high-quality batches free from contaminating hormones, and they reliably induce superovulation across different physiological states, including cycling mares, anestrous mares, and those in seasonal transition. For practitioners managing mares requiring assisted reproductive techniques—or those with stallions of questionable fertility—these protocols can substantially improve pregnancy rates and reproductive efficiency. Understanding the precise timing of gonadotropin interactions and appropriate application across different breeding seasons and reproductive states is now more achievable with recombinant technology than with the unpredictable results that characterised earlier hormonal approaches.
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Practical Takeaways
- •Recombinant gonadotropins offer a consistent, contamination-free alternative to older hormone protocols for superovulation, improving predictability of mare reproductive response
- •Consider superovulation protocols with reFSH/reLH to increase fertility outcomes in subfertile mares or when working with subfertile stallions
- •These technologies enable access to multiple reproductive techniques beyond natural breeding, expanding options for breeding programs with challenged fertility
Key Findings
- •Recombinant equine FSH (reFSH) and recombinant equine LH (reLH) enable reliable superovulation in mares across cycling, anestrous, and transitional reproductive states
- •Recombinant gonadotropin technology produces hormone preparations free of contaminants and other hormones, improving consistency compared to historical protocols
- •Superovulation using reFSH and reLH can enhance pregnancy rates in subfertile mares and improve reproductive efficiency when using semen from subfertile stallions
- •Recombinant gonadotropins support multiple advanced reproductive technologies including embryo transfer, ICSI, oocyte transfer, GIFT, and cloning