Abstract
GonaCon, a single-shot injectable immunocontraceptive vaccine targeting the gonadotropin-releasing hormone (GnRH), has been tested in key mammal species in the UK and shown to be a safe method to reduce population size in areas of high human wildlife conflict. Badgers exhibit an unusual reproductive physiology in that females may maintain fertilised eggs and dormant blastocysts at any time of year and delay their implantation until the winter. It is thus necessary to evaluate the consequences of delayed implantation and timing of vaccination on the effectiveness of GonaCon for fertility control of female badgers. We found that vaccination in June had an immediate effect on the fertility indicators monitored and inhibited subsequent cub production in the following year, while vaccination in November had no effect. Further results suggest that the optimal vaccination window in badgers could be as narrow as between June and August. The longer-term effectiveness of GonaCon vaccination in female badgers appears to reflect maintenance of anti-GnRH antibody titres at or above a putative threshold titre of 1:128,000, a threshold higher than that reported for other species (1:64,000). While it is possible that using a larger dose (> 1 mL) might lead to longer lasting effects, this study shows that vaccination would need to be repeated at least every 2 years in order to maintain levels of female infertility predicted to have demographic impacts on badger populations. Overall, no negative welfare consequences were observed in vaccinated badgers indicating that GonaCon is a potential tool for the management of conflicts involving badgers.
Highlights
Fertility control offers a potential non-lethal approach for reducing mammal abundance in the resolution of conflicts between wildlife and human interests (Fagerstone et al 2010; Massei and Cowan 2014)
This has culminated with the formulation of the single-shot injectable immunocontraceptive gonadotropinreleasing hormone (GnRH) vaccine GonaCon, registered in the USA for white tailed-deer (Odocoileus virginianus), feral horses (Equus caballus) and burros (Equus asinus) in the USA
GonaCon generates antibodies to the gonadotropinreleasing hormone (GnRH), a key hormone that regulates steroid hormones
Summary
Fertility control offers a potential non-lethal approach for reducing mammal abundance in the resolution of conflicts between wildlife and human interests (Fagerstone et al 2010; Massei and Cowan 2014). Fertility control has the potential disadvantage that it will generally take longer to achieve equivalent population reductions, because infertile animals will remain in the population until they die (Hone 1992). Fertility control can be applied in parallel to other types of disease control interventions It is effective at maintaining populations at an appropriate lower density after initial reduction by culling (Merrill et al 2003; White et al 1997) and can potentially work synergistically with disease vaccination C. Smith and Cheeseman 2002) with the reduction in young of the year increasing the efficacy of vaccination for disease control GonaCon has been tested in many mammal species and shown to be a safe and effective single-dose GnRH-based immunocontraceptive vaccine (Massei and Cowan 2014; Massei et al 2008)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
