Supression of testicular function in a male Asian elephant (Elephas maximus) treated with gonadotropin-releasing hormone vaccines
| Autor: | Imke Lueders, Peter Rich, Thomas B. Hildebrandt, Charles Gray, Cheryl Niemuller, Stephan Botha |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Male
medicine.medical_specialty Elephants Musth Physiology Gonadotropin-releasing hormone Biology Semen collection Gonadotropin-Releasing Hormone chemistry.chemical_compound Elephas Asian elephant Internal medicine Testis medicine Animals Testosterone Contraception Immunologic Immunization Schedule Vaccines General Veterinary General Medicine biology.organism_classification Endocrinology Castration chemistry Animal Science and Zoology Spermatogenesis Orchiectomy |
| Zdroj: | Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians. 45(3) |
| ISSN: | 1042-7260 |
| Popis: | The ability to control testosterone concentrations and sperm production is of great interest in both Asian (Elephas maximus) and African (Loxodonta africana) elephants. GnRH vaccination may pose an alternative to surgical castration. This is a case report of a male Asian elephant treated with two commercial GnRH vaccines (Equity and Improvac). Beginning at the age of 7 yr, the male was vaccinated monthly for 6 consecutive months, then every 6 mo and, finally, every 12 to 24 mo over a period of 6 yr. In order to evaluate the GnRH vaccine as a potential method of immunologic castration, behavioral observations, testosterone level analysis, body weights, ultrasound examinations, and semen collection were part of the routine monitoring of this bull (no. 1) and a half-brother (bull 2) who remained untreated and served as control. The results showed a decrease in serum testosterone concentrations after the second booster. Levels stayed continuously below 5.0 ng/ml within the study period. The combined testicle diameter of 9.03 +/- 0.3 cm prior to treatment had decreased to a size of 6.93 +/- 0.19 cm (P0.001) when measured 2 yr later. Accessory sex gland fluid content disappeared and penile atrophy was observed. Semen collections yielded no spermatozoa 1 yr after the initial treatment. Bull 1 showed slowed weight gain as compared to bull 2 and, due to its friendly temperament and the absence of musth, remained in free contact. This report documents the GnRH vaccine as a possible noninvasive and inexpensive method for immune-castration. |
| Databáze: | OpenAIRE |
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