{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T15:02:51Z","timestamp":1789570971538,"version":"build-2803163510"},"reference-count":35,"publisher":"Akademiai Kiado Zrt.","issue":"3","content-domain":{"domain":["www.akjournals.com"],"crossmark-restriction":true},"short-container-title":["AVET"],"published-print":{"date-parts":[[2026,9,16]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>The aim of this study was to obtain an overview of applied contraceptive methods, with a special focus on the gonadotropin-releasing hormone (GnRH) vaccination with Improvac\u00ae, in animals in zoological institutions in German-speaking countries. A survey was prepared inquiring commonly vaccinated species, application intervals and booster vaccinations over the past 11 years and sent to 84 zoological facilities. The questionnaire was answered by the respective veterinarians of 21 zoos (response rate 25%). In the study period, the GnRH vaccine was used in 188 individuals of 42 mammalian species. Bovids were vaccinated the most frequently, followed by giraffes, equids and camelids. Application intervals varied widely between zoos and animal species. The most frequently cited reasons for contraception were population management and breeding exclusion on the recommendation of the EAZA Ex situ Programmes. Undesirable pregnancies during vaccination were observed in 17 individuals (12.1%). Three animals successfully produced offspring after cessation of GnRH vaccination. Most common side effects after the injections were a localised swelling, slight lameness and sexual hyperactivity in some male individuals. It can be concluded that contraception with Improvac\u00ae is common in zoological institutions, although no consistent vaccination scheme was identified for most species.<\/jats:p>","DOI":"10.1556\/004.2026.01295","type":"journal-article","created":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T12:09:10Z","timestamp":1788350950000},"page":"284-292","update-policy":"https:\/\/doi.org\/10.1556\/policypage.crossmark.crossref.2","source":"Crossref","is-referenced-by-count":0,"title":["Contraception of zoo animals using Improvac\u00ae in German-speaking countries \u2013 A questionnaire survey"],"prefix":"10.1556","volume":"74","author":[{"given":"Anja","family":"Hantschmann","sequence":"first","affiliation":[{"name":"Zoo Leipzig GmbH, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8946-6699","authenticated-orcid":true,"given":"Tatjana","family":"Sattler","sequence":"additional","affiliation":[{"name":"Universit\u00e4t Leipzig, Klinik f\u00fcr Klauentiere, Abteilung Schweine und Reproduktionsbiologie, An den Tierkliniken 11, 04103 Leipzig, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"425","reference":[{"key":"B1","series-title":"J. Zoo Wildl. Med.","doi-asserted-by":"publisher","first-page":"427","DOI":"10.1638\/2020-0217","article-title":"Deslorelin (Suprelorin\u00ae) use in North American and European Zoos and Aquariums: taxonomic scope, dosing, and efficacy","volume":"52","author":"Agnew, M. K.","year":"2021","unstructured":"Agnew, M. K., Asa, C. S., Franklin, A. D., McDonald, M. M. and Cowl, V. (2021): Deslorelin (Suprelorin\u00ae) use in North American and European Zoos and Aquariums: taxonomic scope, dosing, and efficacy. J. Zoo Wildl. Med. 52, 427\u2013436. 10.1638\/2020-0217https:\/\/doi.org\/10.1638\/2020-0217"},{"key":"B2","series-title":"Reprod. Biol. Endocrinol.","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1186\/1477-7827-10-63","article-title":"Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana) treated with a gonadotropin-releasing hormone (GnRH) vaccine for inducing anoestrus","volume":"10","author":"Benavides Valades, G.","year":"2012","unstructured":"Benavides Valades, G., Ganswindt, A., Annandale, H., Schulman, M. L. and Bertschinger, H. J. (2012): Non-invasive assessment of the reproductive cycle in free-ranging female African elephants (Loxodonta africana) treated with a gonadotropin-releasing hormone (GnRH) vaccine for inducing anoestrus. Reprod. Biol. Endocrinol. 10, 63\u201373. 10.1186\/1477-7827-10-63https:\/\/doi.org\/10.1186\/1477-7827-10-63"},{"key":"B3","series-title":"Bothalia Afr. Biodiversity & Conversation","doi-asserted-by":"publisher","first-page":"1","DOI":"10.4102\/abc.v48i2.2320","article-title":"Use of anti-gonadotropin-releasing hormone vaccines in African elephants (Loxodonta africana): a review","volume":"48","author":"Bertschinger, H. J.","year":"2018","unstructured":"Bertschinger, H. J. and Lueders, I. (2018): Use of anti-gonadotropin-releasing hormone vaccines in African elephants (Loxodonta africana): a review. Bothalia Afr. Biodiversity & Conversation 48, 1\u20139. 10.4102\/abc.v48i2.2320https:\/\/doi.org\/10.4102\/abc.v48i2.2320"},{"key":"B4","series-title":"Gonadotropin-releasing hormone (GnRH): Production, Structure and Functions","first-page":"85","article-title":"Contraceptive applications of GnRH analogs and vaccines for wildlife mammals of southern Africa: current experience and future challenges","author":"Bertschinger, H. J.","year":"2013","unstructured":"Bertschinger, H. J. and Scott-Sills, E. (2013): Contraceptive applications of GnRH analogs and vaccines for wildlife mammals of southern Africa: current experience and future challenges. In Scott-Sills, E. (ed.), Gonadotropin-releasing hormone (GnRH): Production, Structure and Functions (pp. 85\u2013108). Hauppage, USA: Nova Science Publishers."},{"key":"B5","series-title":"Acta Vet. Scand.","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1186\/1751-0147-54-33","article-title":"Effect of active immunization against GnRH on testosterone concentration, libido and sperm quality in mature AI boars","volume":"54","author":"Bilskis R.","year":"2012","unstructured":"Bilskis R., Sutkeviciene N., Riskeviciene V., Januskauskas A. and Zilinskas H. (2012): Effect of active immunization against GnRH on testosterone concentration, libido and sperm quality in mature AI boars. Acta Vet. Scand. 54, 33. 10.1186\/1751-0147-54-33https:\/\/doi.org\/10.1186\/1751-0147-54-33"},{"key":"B6","series-title":"Wildl. Res.","doi-asserted-by":"publisher","first-page":"548","DOI":"10.1071\/WR07136","article-title":"The use of a GnRH vaccine to suppress mare ovarian activity in a large group of mares under field conditions","volume":"35","author":"Botha, A. A.","year":"2008","unstructured":"Botha, A. A., Schulman, M. L., Bertschinger, H. J., Guthrie, A. J., Annandale, C. H. and Hughes, S. B. (2008): The use of a GnRH vaccine to suppress mare ovarian activity in a large group of mares under field conditions. Wildl. Res. 35, 548\u2013554. 10.1071\/WR07136https:\/\/doi.org\/10.1071\/WR07136"},{"key":"B7","series-title":"J. Vet. Med.","doi-asserted-by":"publisher","first-page":"125","DOI":"10.1046\/j.1439-0442.2002.00427.x","article-title":"Immunization against GnRH in mature mares: antibody titres, ovarian function, hormonal levels and oestrus behaviour","volume":"49","author":"Dalin, A. M.","year":"2002","unstructured":"Dalin, A. M., Andresen, \u00d8. and Malmgren, L. (2002): Immunization against GnRH in mature mares: antibody titres, ovarian function, hormonal levels and oestrus behaviour. J. Vet. Med. 49, 125\u2013131. 10.1046\/j.1439-0442.2002.00427.xhttps:\/\/doi.org\/10.1046\/j.1439-0442.2002.00427.x"},{"key":"B8","series-title":"Theriogenology","doi-asserted-by":"publisher","first-page":"342","DOI":"10.1016\/j.theriogenology.2015.03.025","article-title":"Use of an anti-GnRF vaccine to suppress estrus in crossbred Iberian female pigs","volume":"84","author":"Dalmau, A.","year":"2015","unstructured":"Dalmau, A., Velarde, A., Rodr\u00edguez, P., Pedernera, C., Llonch, P., F\u00e0brega, E., Casal, N., Mainau, E., Gispert, M., King, V., Slootmans, N., Thomas, A. and Mombarg, M. (2015): Use of an anti-GnRF vaccine to suppress estrus in crossbred Iberian female pigs. Theriogenology 84, 342\u2013347. 10.1016\/j.theriogenology.2015.03.025https:\/\/doi.org\/10.1016\/j.theriogenology.2015.03.025"},{"key":"B9","series-title":"J. Vaccines","doi-asserted-by":"publisher","DOI":"10.1155\/2013\/181834","article-title":"Effects of a commercial canine gonadotropin releasing hormone vaccination on intact male llamas and alpacas","volume":"2013","author":"Donovan, C. E.","year":"2013","unstructured":"Donovan, C. E., Grossman, J. L., Patton, K. M., Lamb, S., Bobe, G. and Kutzler, M. A. (2013): Effects of a commercial canine gonadotropin releasing hormone vaccination on intact male llamas and alpacas, J. Vaccines, 2013, 181834. 10.1155\/2013\/181834https:\/\/doi.org\/10.1155\/2013\/181834"},{"key":"B10","series-title":"J. Anim. Sci.","doi-asserted-by":"publisher","first-page":"2524","DOI":"10.2527\/2001.79102524x","article-title":"Vaccination of boars with a GnRH vaccine (Improvac) eliminates boar taint and increases growth performance","volume":"79","author":"Dunshea, F. R.","year":"2001","unstructured":"Dunshea, F. R., Colantoni, C., Howard, K., McCauley, I., Jackson, P., Long, K. A., Lopaticki, S., Nugent, E. A., Simsons, J. A., Walker, J. and Hennessy, D. P. (2001): Vaccination of boars with a GnRH vaccine (Improvac) eliminates boar taint and increases growth performance. J. Anim. Sci. 79, 2524\u20132535. 10.2527\/2001.79102524xhttps:\/\/doi.org\/10.2527\/2001.79102524x"},{"key":"B11","article-title":"Ex situ programs","author":"EAZA","year":"2024a","unstructured":"EAZA. (2024a): Ex situ programs, https:\/\/www.eaza.net\/conservation\/programmes, last access April 09th, 2024."},{"key":"B12","series-title":"Recommendations of the Reproductive Management Group","author":"EAZA","year":"2024b","unstructured":"EAZA. (2024b): Recommendations of the Reproductive Management Group. https:\/\/eazarmg.org\/documents, last access April 09th, 2024."},{"key":"B13","series-title":"Theriogenology","doi-asserted-by":"publisher","first-page":"1102","DOI":"10.1016\/j.theriogenology.2012.05.005","article-title":"Immunization against GnRH in the male camel (Camelus dromedaries): effects on sexual behaviour, testicular volume, semen characteristics and serum testosterone concentrations","volume":"78","author":"Ghoneim, I. M.","year":"2012","unstructured":"Ghoneim, I. M., Waheed, M. M., Al-Eknah, M. M. and El-Bahr, S. M. (2012): Immunization against GnRH in the male camel (Camelus dromedaries): effects on sexual behaviour, testicular volume, semen characteristics and serum testosterone concentrations. Theriogenology 78, 1102\u20131109. 10.1016\/j.theriogenology.2012.05.005https:\/\/doi.org\/10.1016\/j.theriogenology.2012.05.005"},{"key":"B14","series-title":"Front. Biosci. Scholar","doi-asserted-by":"publisher","first-page":"357","DOI":"10.2741\/S492","article-title":"Wildlife population management: are contraceptive vaccines a feasible proposition?","volume":"9","author":"Gupta, S. K.","year":"2017","unstructured":"Gupta, S. K. and Minhas, V. (2017): Wildlife population management: are contraceptive vaccines a feasible proposition? Front. Biosci. Scholar, 9, 357\u2013374. 10.2741\/S492https:\/\/doi.org\/10.2741\/S492"},{"key":"B15","series-title":"PLoS ONE","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0157963","article-title":"Ovarian down regulation by GnRF vaccination decreases reproductive tract tumour size in female white and greater one-horned rhinoceroses","volume":"11","author":"Hermes R.","year":"2016","unstructured":"Hermes R., Schwarzenberger F., G\u00f6ritz F., Oh S., Fernandes T., Bernardino R., Leclerc, A., Greunz, E., Mathew, A., Forsyth, S., Saragusty, J. and Hildebrandt, T. B. (2016): Ovarian down regulation by GnRF vaccination decreases reproductive tract tumour size in female white and greater one-horned rhinoceroses. PLoS ONE 11, e0157963. 10.1371\/journal.pone.0157963https:\/\/doi.org\/10.1371\/journal.pone.0157963"},{"key":"B16","series-title":"Theriogenology","doi-asserted-by":"publisher","first-page":"1866","DOI":"10.1016\/j.theriogenology.2006.04.038","article-title":"Influence of immunization against GnRH on reproductive cyclicity and estrous behavior in the mare","volume":"66","author":"Imboden, I.","year":"2006","unstructured":"Imboden, I., Janett, F., Burger, D., Crowe, M. A., H\u00e4ssig, M. and Thun, R. (2006). Influence of immunization against GnRH on reproductive cyclicity and estrous behavior in the mare. Theriogenology 66, 1866\u20131875. 10.1016\/j.theriogenology.2006.04.038https:\/\/doi.org\/10.1016\/j.theriogenology.2006.04.038"},{"key":"B17","series-title":"Zoo Animal and Wildlife Immobilization and Anaesthesia","first-page":"155","article-title":"Remote drug delivery","author":"Isaza, R.","year":"2014","unstructured":"Isaza, R. (2014). Remote drug delivery. In West, G., Heard, D. and Caulkett, N. (eds), Zoo Animal and Wildlife Immobilization and Anaesthesia. 2nd ed, Chapter 11, pp. 155\u2013169. John Wiley & Sons, Inc."},{"key":"B18","series-title":"Curr. Drug Deliv.","doi-asserted-by":"publisher","first-page":"291","DOI":"10.2174\/1567201043334641","article-title":"Drug delivery to captive Asian elephants - treating Goliath","volume":"1","author":"Isaza, R.","year":"2004","unstructured":"Isaza, R. and Hunter, R. P. (2004): Drug delivery to captive Asian elephants - treating Goliath. Curr. Drug Deliv. 1, 291\u2013298. 10.2174\/1567201043334641https:\/\/doi.org\/10.2174\/1567201043334641"},{"key":"B19","series-title":"Anim. Reprod. Sci.","doi-asserted-by":"publisher","first-page":"88","DOI":"10.1016\/j.anireprosci.2008.11.01","article-title":"Suppression of testicular function and sexual behavior by vaccination against GnRH (EquityTM) in the adult stallion","volume":"115","author":"Janett, F.","year":"2009","unstructured":"Janett, F., Stumpf, R., Burger, D. and Thun, R. (2009): Suppression of testicular function and sexual behavior by vaccination against GnRH (EquityTM) in the adult stallion. Anim. Reprod. Sci. 115, 88\u2013102. 10.1016\/j.anireprosci.2008.11.01https:\/\/doi.org\/10.1016\/j.anireprosci.2008.11.01"},{"key":"B20","series-title":"Am. J. Reprod. Immunol.","doi-asserted-by":"publisher","first-page":"40","DOI":"10.1111\/j.1600-0897.2011.01003.x","article-title":"Contraceptive vaccines for wildlife: a review","volume":"66","author":"Kirkpatrick, J. F.","year":"2011","unstructured":"Kirkpatrick, J. F., Lyda, R. O. and Frank, K. M. (2011): Contraceptive vaccines for wildlife: a review. Am. J. Reprod. Immunol. 66, 40\u201350. 10.1111\/j.1600-0897.2011.01003.xhttps:\/\/doi.org\/10.1111\/j.1600-0897.2011.01003.x"},{"key":"B21","series-title":"J. Zoo Wildl. Med.","first-page":"611","article-title":"Suppression of testicular function in a\u00a0male Asian elephant (Elephas maximus) treated with gonadotropin-releasing hormone vaccines","volume":"45","author":"Lueders, I.","year":"2014","unstructured":"Lueders, I., Hildebrandt, T. B., Gray, C., Botha, S., Rich, P. and Niemueller, C. (2014): Suppression of testicular function in a\u00a0male Asian elephant (Elephas maximus) treated with gonadotropin-releasing hormone vaccines. J. Zoo Wildl. Med. 45, 611\u2013619. https:\/\/www.jstor.org\/stable\/24551189."},{"key":"B22","series-title":"PLoS One","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0178270","article-title":"Effects of GnRH vaccination in wild and captive African elephant bulls (Loxodonta africana) on reproductive organs and semen quality","volume":"12","author":"Lueders, I.","year":"2017","unstructured":"Lueders, I., Young, D., Maree, L., van der Horst, G., Luther, I., Botha, S., Tindall, B., Fosgate, G., Ganswindt, A. and Bertschinger, H. J. (2017): Effects of GnRH vaccination in wild and captive African elephant bulls (Loxodonta africana) on reproductive organs and semen quality. PLoS One, 12, e0178270. 10.1371\/journal.pone.0178270https:\/\/doi.org\/10.1371\/journal.pone.0178270"},{"key":"B23","series-title":"Journal of Zoo and Aquarium Research","doi-asserted-by":"publisher","first-page":"210","DOI":"10.19227\/jzar.v10i4.671","article-title":"Effect of immunocastration with a gonadotropin-releasing hormone vaccine in a male zebra Equus quagga boehmi","volume":"10","author":"Mart\u00ednez-Bov\u00ed, R.","year":"2022","unstructured":"Mart\u00ednez-Bov\u00ed, R., Barba, M., Plaza-D\u00e1vila, M., Barja, I., Carbonell, D., Gerique, C. and Guill\u00e9n-Salazar, F. (2022): Effect of immunocastration with a gonadotropin-releasing hormone vaccine in a male zebra Equus quagga boehmi. Journal of Zoo and Aquarium Research 10, 210\u2013214. 10.19227\/jzar.v10i4.671https:\/\/doi.org\/10.19227\/jzar.v10i4.671"},{"key":"B24","series-title":"J. Zoo Wildl. Med.","doi-asserted-by":"publisher","first-page":"721","DOI":"10.1638\/2019-0098","article-title":"Effects of a GNRH vaccine (Improvac\u00ae) on Patagonian (Otaria byronia) and California sea lions (Zalophus Californianus)","volume":"52","author":"Martinez-Gim\u00e9nez, J.","year":"2021","unstructured":"Martinez-Gim\u00e9nez, J., Ferrero-Vicente, L. and Feltrer-Rambaud, Y. (2021): Effects of a GNRH vaccine (Improvac\u00ae) on Patagonian (Otaria byronia) and California sea lions (Zalophus Californianus). J. Zoo Wildl. Med. 52, 721\u2013725. 10.1638\/2019-0098https:\/\/doi.org\/10.1638\/2019-0098"},{"key":"B25","series-title":"J. Wildl. Dis.","doi-asserted-by":"publisher","first-page":"725","DOI":"10.7589\/0090-3558-40.4.725","article-title":"Contraception of bison by GnRH vaccine: a possible means of decreasing transmission of brucellosis in bison","volume":"40","author":"Miller, L. A.","year":"2004","unstructured":"Miller, L. A., Rhyan, J. C. and Drew, M. (2004): Contraception of bison by GnRH vaccine: a possible means of decreasing transmission of brucellosis in bison. J. Wildl. Dis. 40, 725\u2013730. 10.7589\/0090-3558-40.4.725https:\/\/doi.org\/10.7589\/0090-3558-40.4.725"},{"key":"B26","series-title":"J.\u00a0Zoo\u00a0Wildl. Med.","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1638\/1042-7260-44.4S.S84","article-title":"Twenty years of immunocontraceptive research: lessons learned","volume":"44","author":"Miller, L. A.","year":"2013","unstructured":"Miller, L. A., Fegerstone, K. A. and Eckery, D. C. (2013): Twenty years of immunocontraceptive research: lessons learned. J.\u00a0Zoo\u00a0Wildl. Med. 44, 48\u201396. 10.1638\/1042-7260-44.4S.S84https:\/\/doi.org\/10.1638\/1042-7260-44.4S.S84"},{"key":"B27","series-title":"Hum. Reprod.","doi-asserted-by":"publisher","first-page":"3271","DOI":"10.1093\/humrep\/dei256","article-title":"Recent advances in contraceptive vaccine development: a mini review","volume":"20","author":"Naz, R. K.","year":"2005","unstructured":"Naz, R. K., Gupta, S. K., Gupta, J. C., Vyas, H. K. and Talwar, G. P. (2005): Recent advances in contraceptive vaccine development: a mini review. Hum. Reprod. 20, 3271\u20133283. 10.1093\/humrep\/dei256https:\/\/doi.org\/10.1093\/humrep\/dei256"},{"key":"B28","series-title":"Am. J. Reprod. Immunol.","doi-asserted-by":"publisher","first-page":"426","DOI":"10.1111\/aji.12431","article-title":"Immunocontraception for animals: current status and future perspective","volume":"75","author":"Naz, R. K.","year":"2015","unstructured":"Naz, R. K. and Saver, A. E. (2015): Immunocontraception for animals: current status and future perspective. Am. J. Reprod. Immunol. 75, 426\u2013439. 10.1111\/aji.12431https:\/\/doi.org\/10.1111\/aji.12431"},{"key":"B29","series-title":"J. Global Ecol. Environ.","doi-asserted-by":"publisher","first-page":"14","DOI":"10.56557\/jogee\/2022\/v16i17622","article-title":"Modern approaches to contraception in domestic and wild animals: a Review","volume":"16","author":"Padodara, R. J.","year":"2022","unstructured":"Padodara, R. J., Singh V. K., Odedara A. B., Vasava A. A., Sharma A. K. and Mehta V. M. (2022): Modern approaches to contraception in domestic and wild animals: a Review. J. Global Ecol. Environ. 16, 14\u201325. 10.56557\/jogee\/2022\/v16i17622https:\/\/doi.org\/10.56557\/jogee\/2022\/v16i17622"},{"key":"B30","series-title":"Thai J. Vet. Med.","doi-asserted-by":"publisher","first-page":"1","DOI":"10.56808\/2985-1130.2612","article-title":"Effects of immunization against gonadotropin releasing hormone on reproductive functions in male rusa deer (Rusa timorensis)","volume":"45","author":"Phraluk, O.","year":"2015","unstructured":"Phraluk, O., Wajjwalku, W., Siriaroonrat, B., Booddee, O. and Thongtip, N., (2015): Effects of immunization against gonadotropin releasing hormone on reproductive functions in male rusa deer (Rusa timorensis). Thai J. Vet. Med. 45, 1. 10.56808\/2985-1130.2612https:\/\/doi.org\/10.56808\/2985-1130.2612"},{"key":"B31","series-title":"Zoo Biol.","doi-asserted-by":"publisher","first-page":"520","DOI":"10.1002\/zoo.21863","article-title":"The use of gonadotropin releasing hormone to manage intraspecific agonism in a coalition of male lions (Panthera leo)","volume":"43","author":"Picone, S. L.","year":"2024","unstructured":"Picone, S. L., Sherman, W. C., Sadler, R. A., France, N. R., Herman, A., Kinzley, C. and Minier, D. E. (2024): The use of gonadotropin releasing hormone to manage intraspecific agonism in a coalition of male lions (Panthera leo). Zoo Biol. 43, 520\u2013536. 10.1002\/zoo.21863https:\/\/doi.org\/10.1002\/zoo.21863"},{"key":"B32","series-title":"Front. Vet. Sci.","doi-asserted-by":"publisher","DOI":"10.3389\/fvets.2020.569185","article-title":"Case Report: suppression\u00a0of harem stallion behavior and fertility following anti-gonadotropin-releasing hormone vaccination of a captive wild Przewalski\u2019s horse (Equus ferus przewalskii)","volume":"7","author":"Ponthier, J.","year":"2020","unstructured":"Ponthier, J., Rigaux. G., Parrilla-Hernandez, S., Egyptien, S., Gatez C., Carrasco Leroy, C. and Deleuze, S. (2020): Case Report: suppression\u00a0of harem stallion behavior and fertility following anti-gonadotropin-releasing hormone vaccination of a captive wild Przewalski\u2019s horse (Equus ferus przewalskii). Front. Vet. Sci. 7, 569185. 10.3389\/fvets.2020.569185https:\/\/doi.org\/10.3389\/fvets.2020.569185"},{"key":"B33","series-title":"J. Swine Health Prod.","first-page":"250","article-title":"Growth performance and carcass traits of boars raised in Germany and either surgically castrated or vaccinated against gonadotropin-releasing hormone","volume":"17","author":"Schmoll, F.","year":"2009","unstructured":"Schmoll, F., Kauffold, J., Pf\u00fctzer, A., Baumgartner, J., Brock, F., Grodzycki, M. and Andrews, S. (2009): Growth performance and carcass traits of boars raised in Germany and either surgically castrated or vaccinated against gonadotropin-releasing hormone. J. Swine Health Prod. 17, 250\u2013255."},{"key":"B34","series-title":"Zoo Biol.","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1002\/zoo.21651","article-title":"Immunocontraception of male and female giraffes using the GnRH vaccine Improvac\u00ae","volume":"41","author":"Schwarzenberger, F.","year":"2021","unstructured":"Schwarzenberger, F., Kranwinkel, P., Jeserschek, S.-M., Schauerte, N., Geiger, C., Balfanz, F., Knauf-Witzens, T., Sicks, F., Martinez, N. E., Anfray, G., Hein, A., Kaandorp-Huber, C., Marcordes, S. and Vensh\u00f8j, B. (2021): Immunocontraception of male and female giraffes using the GnRH vaccine Improvac\u00ae. Zoo Biol. 41, 1\u201316. 10.1002\/zoo.21651https:\/\/doi.org\/10.1002\/zoo.21651"},{"key":"B35","series-title":"Anim. Reprod. Sci.","doi-asserted-by":"publisher","first-page":"111","DOI":"10.1016\/j.anireprosci.2015.11.019","article-title":"Potential of a gonadotropin-releasing hormone vaccine to suppress musth in captive male Asian\u00a0elephants (Elephas maximus)","volume":"164","author":"Somgird, C.","year":"2016","unstructured":"Somgird, C., Homkong, P., Sripiboon, S., Brown, J. L., Stout, T. A. E., Colenbrander, B., Mahasawangkul, S. and Thitaram, C. (2016): Potential of a gonadotropin-releasing hormone vaccine to suppress musth in captive male Asian\u00a0elephants (Elephas maximus). Anim. Reprod. Sci. 164,\u00a0111\u2013120. 10.1016\/j.anireprosci.2015.11.019https:\/\/doi.org\/10.1016\/j.anireprosci.2015.11.019"}],"container-title":["Acta Veterinaria Hungarica"],"original-title":[],"link":[{"URL":"https:\/\/www.akjournals.com\/view\/journals\/004\/74\/3\/article-p284.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.akjournals.com\/downloadpdf\/journals\/004\/74\/3\/article-p284.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/www.akjournals.com\/downloadpdf\/journals\/004\/74\/3\/article-p284.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T14:10:21Z","timestamp":1789567821000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.akjournals.com\/view\/journals\/004\/74\/3\/article-p284.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,16]]},"references-count":35,"journal-issue":{"issue":"3"},"URL":"https:\/\/doi.org\/10.1556\/004.2026.01295","relation":{},"ISSN":["0236-6290","1588-2705"],"issn-type":[{"value":"0236-6290","type":"print"},{"value":"1588-2705","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,16]]}}}