Deslorelin Slow-Release Implants Delay Ovulation and Increase Plasma AMH Concentration and Small Antral Follicles in Haflinger Mares.
Authors: Kaps Martim, Okada Carolina T C, Gautier Camille M, Aurich Jörg, Aurich Christine
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Deslorelin Implants and Ovarian Follicle Manipulation in Mares Ovum pick-up (OPU) and other assisted reproductive techniques require optimal ovarian conditions, prompting investigation into pharmaceutical manipulation of follicular populations. Researchers administered either a 9.4 mg slow-release deslorelin implant or short-acting 1.25 mg deslorelin to twelve synchronised Haflinger mares, then monitored ovulatory intervals, antral follicle counts (AFC), follicle size distributions, and plasma anti-Müllerian hormone (AMH) concentrations via regular transrectal ultrasonography and blood sampling. The slow-release implant delayed ovulation by approximately seven days (23.8 ± 10.5 days versus 17.0 ± 3.9 days), whilst significantly elevating plasma AMH concentrations and increasing the proportion of small antral follicles, particularly those measuring 10–15 mm in diameter. Although deslorelin showed limited efficacy for complete oestrous suppression in mares, the selective enhancement of small follicle populations—reflected in elevated AMH—suggests potential clinical application for pre-OPU conditioning protocols where the aim is to synchronise cohorts of smaller follicles for aspiration. Practitioners considering assisted reproduction in mares may find slow-release deslorelin a useful adjunct for optimising ovarian conditions prior to collection, though longer-acting formulations or combined protocols warrant further investigation.
Read the full abstract on PubMed
Practical Takeaways
- •Deslorelin slow-release implants can delay ovulation and increase small antral follicles, potentially improving ovum pick-up success rates in mares used for breeding programs
- •The treatment effect on follicle populations is reflected in elevated AMH levels, providing a measurable biomarker for monitoring follicular status during reproductive management
- •While estrus suppression is minimal with this implant dose, the manipulation of small follicle subpopulations makes it a useful tool for timing OPU procedures in mare breeding operations
Key Findings
- •Deslorelin 9.4 mg slow-release implants delayed first ovulation to 23.8 ± 10.5 days compared to 17.0 ± 3.9 days in short-acting control group (p < 0.05)
- •Deslorelin treatment increased plasma AMH concentration over time compared to control (p < 0.05)
- •Deslorelin implants significantly altered follicles in the 10-15 mm diameter range (p < 0.05) with changes in antral follicle count over time
- •9.4 mg deslorelin implants showed minor effects on estrus suppression but promising results for manipulating small ovarian follicle populations prior to OPU