Immunocastration of colts and immunospeying of fillies.
Abstract: A series of experiments using an ovalbumin conjugated gonadotrophin releasing hormone was used to stimulate antibody production, suppress testosterone secretion and depress testicular function in yearling and 2 year old colts and fillies. In the preliminary experiment, an injectable oil-based formulation was administered to yearling colts. Testicular development and testosterone secretion were retarded for a period of approximately 28-32 weeks while antibody titres were greater than 1:1000. An implant and water-soluble vaccine (200 and 400 mg) is presently being tested in 2 year old colts. Testicular dimensions and testosterone concentrations decreased following vaccination. Preliminary results indicate that the effects of the implant are reversible and last for approximately 30 weeks. The water-soluble vaccine produced effective antibodies for 10-19 weeks. Plasma testosterone of all colts was reduced to gelding levels (0.2 ng/mL) while antibody titres were greater than 1:1000. Semen evaluation, morphometric analysis and daily sperm production data indicate that the testes recovered normal function. These experiments are continuing and more definitive data on the vaccine and its reversibility will be available at their conclusion. Ovarian activity of the treated fillies (200 and 400 mg) ceased soon after vaccination. Their progesterone concentrations have remained below 1 ng/mL for 20 weeks. The untreated control fillies have continued to cycle normally as determined by ovarian ultrasonography and progesterone concentrations.
Publication Date: 1993-10-01 PubMed ID: 8270277DOI: 10.1038/icb.1993.55Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The study explores the use of an ovalbumin conjugated gonadotrophin releasing hormone to immunocastrate colts and immunospey fillies. This hormone stimulates antibody production, inhibits testosterone secretion, and depresses testicular and ovarian activity in young horses. Preliminary results suggest that this process may be reversible after approximately 30 weeks.
Experimental Procedure
- The researchers conducted a series of experiments using an ovalbumin conjugated gonadotrophin releasing hormone on yearling and 2 year old colts and fillies.
- In the preliminary experiment, an injectable oil-based formulation of the hormone was administered to yearling colts, which retarded their testicular development and testosterone secretion for about 28-32 weeks while producing substantial antibody titres.
- In subsequent experiments, an implant and a water-soluble vaccine (200 and 400 mg) were tested on 2 year old colts. Post vaccination, the testicular dimensions and testosterone concentrations in the colts decreased.
- Ovarian activity of fillies treated with 200 and 400 mg of the vaccine ceased shortly after the vaccination, maintaining low progesterone concentrations for 20 weeks.
Preliminary Observations and Results
- The effects of the implants appeared to be reversible, lasting for about 30 weeks.
- The water-soluble vaccine generated effective antibodies for 10-19 weeks.
- Plasma testosterone in all colts dropped to gelding levels while antibody titres were substantial.
- A semen evaluation, a morphometric analysis, and daily sperm production data indicated that the testes recovered to normal function.
- The study also revealed cessation of ovarian activity in fillies post vaccination with progesterone concentrations remaining low for about 20 weeks.
- The untreated control fillies continued to have normal ovarian cycles as evidenced by ovarian ultrasonography and progesterone concentrations.
Future Research Direction
- The experiments are ongoing, and definitive data on the vaccine’s full impact and reversibility will be available upon their completion.
Cite This Article
APA
Dowsett KF, Tshewang U, Knott LM, Jackson AE, Trigg TE.
(1993).
Immunocastration of colts and immunospeying of fillies.
Immunol Cell Biol, 71 ( Pt 5), 501-508.
https://doi.org/10.1038/icb.1993.55 Publication
Researcher Affiliations
- Department of Farm Animal Medicine and Production, University of Queensland, St Lucia, Australia.
MeSH Terms
- Animals
- Castration / veterinary
- Contraception, Immunologic / veterinary
- Delayed-Action Preparations
- Female
- Gonadotropin-Releasing Hormone / immunology
- Horses / surgery
- Male
- Ovariectomy / veterinary
- Ovary / physiology
- Random Allocation
- Sperm Count
- Testis / physiology
- Testosterone / metabolism
- Vaccines / immunology
Citations
This article has been cited 2 times.- Han YG, Liu GQ, Jiang XP, Xiang XL, Huang YF, Nie B, Zhao JY, Nabeel I, Tesema B. Reversibility and safety of KISS1 metastasis suppressor gene vaccine in immunocastration of ram lambs. Asian-Australas J Anim Sci 2018 Jun;31(6):835-841.
- Babiuk LA, Potter AA. Veterinary vaccines. Biotechnol Adv 1994;12(3):489-523.
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