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Home / Equine Research Bank / Aust Vet J / Sustained-release deslorelin acetate implants disrupt oestro...
Australian veterinary journal2023; 101(7); 275-278; doi: 10.1111/avj.13244

Sustained-release deslorelin acetate implants disrupt oestrous cyclicity in the mare.

Abstract: There is a need for a safe, effective and practical method of oestrus suppression in the mare. The aim of this study was to monitor ovarian activity in mares exposed to either 9.4 or 28.2 mg deslorelin acetate, a GnRH agonist, in the form of a sustained-release implant. Following oestrus synchronisation, mares were randomly assigned to one of three groups (n = 4 per group) and administered either one (Des1 group; 9.4 mg) or three (Des3 group; 28.2 mg) implants of deslorelin acetate (Suprelorin-12, Virbac Australia) or one blank implant (Control group; Virbac Australia). Mares underwent weekly blood sampling for 12 weeks following implant placement (Day 0-Day 84), with transrectal palpation and ultrasonography of the reproductive tract at all sampling timepoints except Days 56, 70 and 77. All mares showed baseline serum progesterone concentrations (SPC; ≤1.3 nmol/L or 0.4 ng/ml) on Day 0. Cycling Control mares showed typical oestrous cyclicity characterised by peaks and troughs in SPC over time. Four of eight treated mares demonstrated a sustained elevation in SPC after the initial ovulation after implant placement; SPC declined to baseline levels (Des1 group; 2 mares) or remained elevated (Des3 group; 2 mares) at the final sampling timepoint on Day 84. Oestrous cyclicity was erratic in three of the remaining four treated mares. In total, 87.5% (7 of 8) of treated mares showed atypical oestrous cyclicity after implant placement. These results suggest that deslorelin acetate disrupts oestrous cyclicity in the mare, which warrants further research.
© 2023 The Authors. Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.
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Publication Date: 2023-04-16 PubMed ID: 37062896DOI: 10.1111/avj.13244Google Scholar: Lookup
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  • Randomized Controlled Trial
  • Veterinary
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research explores the effect of long-term release deslorelin acetate implants on the oestrous cycles of mares. It indicates substantial disruption of the cycles by the implants, suggesting a potential method for oestrus suppression.

Research Methodology

  • The study aimed to monitor the ovarian activity of mares exposed to two doses of deslorelin acetate (9.4 mg and 28.2 mg). Deslorelin acetate is a GnRH agonist used as part of sustained-release implants.
  • In a controlled experiment, mares were synchronized for oestrus and then divided into three groups. Each group constituted four mares.
  • The first group was administered one implant of deslorelin acetate (Des1 group) containing 9.4 mg of the compound. The second group received three implants (Des3 group) totaling 28.2 mg, and the control group was given one blank implant.
  • Over a period of 12 weeks after the implantation, the mares went through weekly blood sampling. This was coupled with regular transrectal palpation and ultrasonography of the reproductive tract, except on days 56, 70, and 77.

Findings of the Research

  • At the beginning of the experiment (Day 0), all mares showed baseline serum progesterone concentrations (SPC).
  • Throughout the 12 weeks, the control group, which was not administered deslorelin acetate, exhibited typical oestrous cyclicity characterized by variable SPC levels.
  • Four of the eight mares that received the deslorelin acetate (both groups) presented a sustained increase in SPC after the initial ovulation following the implant. These values declined to baseline levels in the Des1 group or remained high in the Des3 group at the end of the 12 weeks.
  • The remaining four treated mares exhibited irregular oestrous cyclicity, with three of them showing erratic cycles.
  • In total, 87.5% of the deslorelin acetate treated mares (7 out of 8) displayed atypical oestrous cyclicity after the implant.

Conclusion

  • The study concludes that deslorelin acetate implants significantly disrupt the oestrous cyclicity in mares. This finding suggests the substance could serve as a method of oestrus suppression, although further research is required to verify and understand this application.

Cite This Article

APA
Joonè CJ, Cavalieri J. (2023). Sustained-release deslorelin acetate implants disrupt oestrous cyclicity in the mare. Aust Vet J, 101(7), 275-278. https://doi.org/10.1111/avj.13244

Publication

Australian veterinary journal
ISSN: 1751-0813
NlmUniqueID: 0370616
Country: England
Language: English
Volume: 101
Issue: 7
Pages: 275-278

Researcher Affiliations

Joonè, C J
  • College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.
Cavalieri, J
  • College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.

MeSH Terms

  • Female
  • Horses
  • Animals
  • Gonadotropin-Releasing Hormone
  • Delayed-Action Preparations
  • Triptorelin Pamoate / adverse effects
  • Ovulation
  • Periodicity

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