Cope Holly R, Peck Sarah, Hobbs Rebecca, Keeley Tamara, Izzard Stephen, Yeen-Yap Wei, White Peter J, Hogg Carolyn J, Herbert Catherine A
School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, J.D. Stewart Building B01, Camperdown, NSW 2006, Australia.
Wildlife Management Branch, Department of Primary Industries, Parks, Water and Environment, Hobart, Tas. 7000, Australia.
Reprod Fertil Dev. 2019 Aug;31(9):1473-1485. doi: 10.1071/RD18407.
Contraception is increasingly used to manage breeding opportunities in conservation-dependent species. This study aimed to determine the efficacy, duration of effect, optimal dose and potential side effects of Suprelorin contraceptive implants in Tasmanian devils, for use in the conservation breeding program. In our pilot study, Suprelorin was found to effectively suppress oestrous cycles in female devils, yet caused a paradoxical increase in testosterone in males. Therefore, we focussed on females in further trials. Females received one (n=5), two (n=5) or no (n=5) Suprelorin implants, with quarterly gonadotrophin-releasing hormone (GnRH) challenges used to test pituitary responsiveness over two breeding seasons. Both Suprelorin doses suppressed pituitary responsiveness for at least one breeding season, with a reduced effect in the second. There was a dose-response effect on duration rather than magnitude of effect, with high-dose devils remaining suppressed for longer than low-dose animals. There were no apparent negative effects on general health, yet captivity and contraception together may cause weight gain. Suprelorin contraceptive implants are now routinely used in the Save the Tasmanian Devil Program insurance metapopulation to meet the aims of maintaining genetic and behavioural integrity by controlling individual reproductive contributions in group housing situations.
在依赖保护的物种中，避孕措施越来越多地被用于控制繁殖机会。本研究旨在确定用于袋獾保护繁殖计划的Suprelorin避孕植入物的功效、作用持续时间、最佳剂量和潜在副作用。在我们的初步研究中，发现Suprelorin能有效抑制雌性袋獾的发情周期，但却导致雄性袋獾的睾酮水平出现反常升高。因此，在后续试验中我们将重点放在了雌性袋獾身上。雌性袋獾分别接受一枚（n = 5）、两枚（n = 5）Suprelorin植入物或不接受植入物（n = 5），并在两个繁殖季节中每季度进行促性腺激素释放激素（GnRH）激发试验以检测垂体反应性。两种Suprelorin剂量均至少在一个繁殖季节内抑制了垂体反应性，在第二个繁殖季节效果有所减弱。对作用持续时间而非作用强度存在剂量反应效应，高剂量组袋獾的抑制时间比低剂量组动物更长。对总体健康没有明显负面影响，但圈养和避孕措施共同作用可能会导致体重增加。Suprelorin避孕植入物现已在拯救袋獾计划的保险复合种群中常规使用，以通过控制群居环境中个体的繁殖贡献来实现维持遗传和行为完整性的目标。
