Suppressing reproductive activity in horses using GnRH vaccines, antagonists or agonists.
Abstract: There are a number of situations in which it is desirable to suppress part or all of the reproductive endocrine system in a horse, notably the competing animal whose tractability during training, or performance during competition, is compromised by the expression of sexual or aggressive behavior. The current therapeutic approaches to reproductive endocrine suppression include gonadectomy and progestagen administration, where the former carries surgical risks and entails irreversible loss of breeding potential, and effective progestagen therapy requires frequent administration for extended periods and is banned in some competing animals as potentially anabolic. In this context, preventing the action of gonadotrophin releasing hormone (GnRH) by blocking its pituitary receptors is an attractive alternative for reversibly rendering mares anestrus or depressing testosterone secretion or spermatogenesis in stallions. This paper reviews the data on effects, efficacy, reversibility, and side effects of GnRH vaccines, antagonists, and agonists for suppressing reproductive activity in horses, within the context of their potential place in the pharmacological armoury of the veterinary clinician.
Publication Date: 2004-07-24 PubMed ID: 15271486DOI: 10.1016/j.anireprosci.2004.04.009Google Scholar: Lookup
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Summary
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This research article explores different scientific methods used to temporarily halt reproductive activities in horses, particularly using GnRH (gonadotrophin releasing hormone) vaccines, antagonists, and agonists. Such methods are deemed beneficial as they help improve the behaviour and performance of competing horses.
Understanding the Research Context
- The paper focuses on situations where it might be beneficial to suppress part or all of the reproductive endocrine system in a horse. This is particularly relevant for competing horses whose behaviour during training or performance could be impacted by sexual or aggressive tendencies.
- In current practice, approaches to suppress the reproductive endocrine system are gonadectomy (castration in males) and progestagen administration. However, these methods are either irreversible and carry potential surgical risks, require regular, extended period of administration and could be potentially anabolic which means they might be banned in competing athletes.
Role of GnRH in Reproductive Activity
- GnRH or gonadotrophin releasing hormone is a hormone that has a key role in initiating reproductive activity in the body. In this study, the focus is on blocking the pituitary receptors of this hormone.
- By blocking these receptors, it’s possible to make mares (female horses) anestrus (not experiencing sexual heat) or reduce testosterone secretion or sperm production in stallions (male horses).
The Use of GnRH Vaccines, Antagonists, and Agonists
- The paper reviews the impact, efficacy, reversibility, and side effects of GnRH vaccines, antagonists and agonists to suppress reproductive activity in horses.
- All these methods focus on the control of GnRH activity, potentially making them reversible and reducing the risk of permanent reproductive damage or other adverse effects of current therapeutic approaches.
Implication for Veterinary Clinician
- Understanding the application, effects and potential side effects of these GnRH-based strategies can help veterinary clinicians make more informed decisions about managing the reproductive activities in horses.
- It could allow for better behavior and performance management in competing horses and overall, improving their quality of life.
Cite This Article
APA
Stout TA, Colenbrander B.
(2004).
Suppressing reproductive activity in horses using GnRH vaccines, antagonists or agonists.
Anim Reprod Sci, 82-83, 633-643.
https://doi.org/10.1016/j.anireprosci.2004.04.009 Publication
Researcher Affiliations
- Department of Equine Sciences, Section of Reproduction, Utrecht University, Yalelaan 12, 3584 CM Utrecht, The Netherlands. t.a.e.stout@vet.uu.nl
MeSH Terms
- Anestrus
- Animals
- Behavior, Animal
- Contraception / veterinary
- Female
- Gonadotropin-Releasing Hormone / agonists
- Gonadotropin-Releasing Hormone / antagonists & inhibitors
- Gonadotropin-Releasing Hormone / immunology
- Horses / physiology
- Male
- Reproduction / physiology
- Sexual Behavior, Animal / drug effects
- Sexual Behavior, Animal / physiology
- Spermatogenesis-Blocking Agents
- Testosterone / antagonists & inhibitors
- Vaccines / administration & dosage
Citations
This article has been cited 8 times.- Pan F, Du H, Tian W, Xie H, Zhang B, Fu W, Li Y, Ling Y, Zhang Y, Fang F, Liu Y. Effect of GnRH immunocastration on immune function in male rats. Front Immunol 2022;13:1023104.
- Botha AE, Schulman ML, Birrell J, du Plessis L, Laver PN, Soley J, Colenbrander B, Bertschinger HJ. Effects of an anti-gonadoliberin releasing hormone vaccine on testicular, epididymal and spermatogenic development in the horse. Reprod Domest Anim 2022 Aug;57(8):919-927.
- Aurich C, Kaps M. Suppression of reproductive behaviour and gonadal function in female horses-An update. Reprod Domest Anim 2022 Sep;57 Suppl 4(Suppl 4):4-12.
- Schwarzenberger F, Krawinkel P, Jeserschek SM, Schauerte N, Geiger C, Balfanz F, Knauf-Witzens T, Sicks F, Martinez Nevado E, Anfray G, Hein A, Kaandorp-Huber C, Marcordes S, Venshøj B. Immunocontraception of male and female giraffes using the GnRH vaccine Improvac®. Zoo Biol 2022 Jan;41(1):50-64.
- Meeusen EN, Walker J, Peters A, Pastoret PP, Jungersen G. Current status of veterinary vaccines. Clin Microbiol Rev 2007 Jul;20(3):489-510, table of contents.
- Tyrnenopoulou P, Flouraki E, Folias L, Loukopoulos E, Starras A, Chalvatzis P, Tsioli V, Mavrogianni VS, Fthenakis GC. Complications Following Orchiectomy in Stallions in Field Conditions: Descriptive Results and Predictors in a Study of 612 Cases. Animals (Basel) 2026 Jan 21;16(2).
- Wolf N, Hahn JA, Walter I, Zablotski Y, Zerbe H, Witte TS. Pathohistological Findings after Bilateral Ovariectomy in Mares with Behavioral Problems. Animals (Basel) 2024 Oct 8;14(19).
- Khumsap S, Tangtrongsup S, Towiboon P, Somgird C. GnRH Vaccine Could Suppress Serum Testosterone in Stallion Mules. Animals (Basel) 2024 Jun 17;14(12).
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