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

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dc.contributor.author Valades, Gabriela Benavides
dc.contributor.author Ganswindt, Andre
dc.contributor.author Annandale, C.H. (Cornelius Henry)
dc.contributor.author Schulman, M.L. (Martin)
dc.contributor.author Bertschinger, H.J. (Hendrik Jan)
dc.date.accessioned 2013-01-23T08:55:26Z
dc.date.available 2013-01-23T08:55:26Z
dc.date.issued 2012-08-25
dc.description.abstract BACKGROUND: In southern Africa, various options to manage elephant populations are being considered. Immunocontraception is considered to be the most ethically acceptable and logistically feasible method for control of smaller and confined populations. In this regard, the use of gonadotropin-releasing hormone (GnRH) vaccine has not been investigated in female elephants, although it has been reported to be safe and effective in several domestic and wildlife species. The aims of this study were to monitor the oestrous cycles of free-ranging African elephant cows using faecal progestagen metabolites and to evaluate the efficacy of a GnRH vaccine to induce anoestrus in treated cows. METHODS: Between May 2009 - June 2010, luteal activity of 12 elephant cows was monitored non-invasively using an enzyme immunoassay detecting faecal 5alpha-reduced pregnanes (faecal progestagen metabolites, FPM) on a private game reserve in South Africa. No bulls of breeding age were present on the reserve prior to and for the duration of the study. After a 3-month control period, 8 randomly-selected females were treated twice with 600 micrograms of GnRH vaccine (ImprovacW, Pfizer Animal Health, Sandton, South Africa) 5-7 weeks apart. Four of these females had been treated previously with the porcine zona pellucida (pZP) vaccine for four years (2004-2007). RESULTS: All 12 monitored females (8 treated and 4 controls) showed signs of luteal activity as evidenced by FPM concentrations exceeding individual baseline values more than once. A total of 16 oestrous cycles could be identified in 8 cows with four of these within the 13 to 17 weeks range previously reported for captive African elephants. According to the FPM concentrations the GnRH vaccine was unable to induce anoestrus in the treated cows. Overall FPM levels in samples collected during the wet season (mean 4.03 micrograms/gram dry faeces) were significantly higher (P<0.002) than the dry season (mean 2.59 micrograms/gram dry faeces). CONCLUSIONS: The GnRH vaccination protocol failed to induce anoestrus in the treated female elephants. These results indicate that irregular oestrous cycles occur amongst free-ranging elephants and are not restricted to elephants in captivity. The relationship between ecological conditions and endocrine activity were confirmed. Free-ranging female elephants were observed to not cycle continuously throughout the year in the absence of adult bulls. en
dc.description.librarian ab2012 en
dc.description.librarian ab2013 (Author correction)
dc.description.librarian ab2013 (Author correction)
dc.description.uri http://www.rbej.com/content/10/1/63 en
dc.identifier.citation Benavides Valades et al.: 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. Reproductive Biology and Endocrinology 2012 10:63. en
dc.identifier.issn 1477-7827
dc.identifier.other 10.1186/1477-7827-10-63
dc.identifier.other 6507085906
dc.identifier.other G-9856-2014
dc.identifier.uri http://hdl.handle.net/2263/20886
dc.language.iso en en
dc.publisher BioMed Central en
dc.relation.requires Adobe Acrobat Reader en
dc.rights © 2012 Benavides Valades et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License en
dc.subject GnRH immunocontraception en
dc.subject African elephant cows en
dc.subject Oestrous cycle en
dc.subject Non-invasive monitoring en
dc.subject Faecal progestagen metabolites en
dc.subject Ecological effects en
dc.subject Loxodonta africana en
dc.subject.lcsh African elephant -- Vaccination en
dc.subject.lcsh Vaccination of animals en
dc.subject.lcsh African elephant -- Reproduction -- Endocrine aspects en
dc.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 en
dc.type Article en


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