{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T13:23:51Z","timestamp":1791638631822,"version":"4.3.4"},"reference-count":31,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2022,5,12]],"date-time":"2022-05-12T00:00:00Z","timestamp":1652313600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Reprod Domestic Animals"],"published-print":{"date-parts":[[2022,8]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The effects of the GnRH vaccine Improvac<jats:sup>\u00ae<\/jats:sup> on testicular and epididymal morphometrics, histology and spermatogenesis were measured in 19 young (15\u201320\u00a0months) colts randomly assigned to one control (saline, castration at 57\u00a0days, <jats:italic>n<\/jats:italic>\u00a0=\u00a06) or either of two GnRH vaccine\u2010treatment groups, T\u201057 (castration at 57\u00a0days, <jats:italic>n<\/jats:italic>\u00a0=\u00a07) or T\u2010100 (castration at 100\u00a0days, <jats:italic>n<\/jats:italic>\u00a0=\u00a06), respectively. All were immunized on Day 0 with a single booster on Day 28. Excised testes and epididymides were weighed and processed for histology to measure tubule, epithelial and muscle dimensions, the ratio of interstitial tissue to seminiferous tubules and determine the stage of spermatogenesis. Testis volume, unchanged within controls, decreased in T\u201057 and T\u2010100 groups by 50% and 70%, respectively. Treated colts' testes were significantly lighter than controls (64% relative difference); however, epididymal mass showed no significant differences between groups. Proportionally less seminiferous tubule relative to interstitial tissue was observed in both treatment groups (5%) versus controls (22%) with a mean tubule size 28% smaller than controls. Controls exhibited a high proportion of seminiferous tubules with advanced stages of spermatogenesis, whereas treated colts showed a high proportion of tubules in the early stages of spermatogenesis. In conclusion, immunization against GnRH in prepubertal colts was effective at reducing the development of their intra\u2010scrotal reproductive organs and preventing normal spermatogenesis. GnRH vaccination of young colts effectively and consistently reduced testis mass, tubule size and relative proportion of seminiferous tubule tissue while retarding spermatogenesis. The epididymis showed changes with a smaller tubule diameter, lower epithelial height and thicker muscle layer recorded in treated compared to control colts.<\/jats:p>","DOI":"10.1111\/rda.14141","type":"journal-article","created":{"date-parts":[[2022,5,2]],"date-time":"2022-05-02T19:34:56Z","timestamp":1651520096000},"page":"919-927","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Effects of an anti\u2010gonadoliberin releasing hormone vaccine on testicular, epididymal and spermatogenic development in the horse"],"prefix":"10.1111","volume":"57","author":[{"given":"Alma E.","family":"Botha","sequence":"first","affiliation":[{"name":"Section of Reproduction Department of Production Animal Studies Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0285-8679","authenticated-orcid":false,"given":"Martin L.","family":"Schulman","sequence":"additional","affiliation":[{"name":"Section of Reproduction Department of Production Animal Studies Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"},{"name":"Veterinary Population Management Laboratory Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Birrell","sequence":"additional","affiliation":[{"name":"Veterinary Division South African Police Services  Pretoria South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lizette","family":"du Plessis","sequence":"additional","affiliation":[{"name":"Electron Microscope Unit Department of Anatomy and Physiology Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter N.","family":"Laver","sequence":"additional","affiliation":[{"name":"Electron Microscope Unit Department of Anatomy and Physiology Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Soley","sequence":"additional","affiliation":[{"name":"Electron Microscope Unit Department of Anatomy and Physiology Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ben","family":"Colenbrander","sequence":"additional","affiliation":[{"name":"Equine Sciences Department Faculty of Veterinary Medicine University of Utrecht  Utrecht The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8949-1990","authenticated-orcid":false,"given":"Henk J.","family":"Bertschinger","sequence":"additional","affiliation":[{"name":"Section of Reproduction Department of Production Animal Studies Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"},{"name":"Veterinary Population Management Laboratory Faculty of Veterinary Science University of Pretoria  Onderstepoort South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,5,12]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1210\/endo\u201093\u20105\u20101092"},{"key":"e_1_2_9_3_1","first-page":"85","volume-title":"Gonadotropinreleasing hormone (GnRH). 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