Marine Mammal Research Group, Graduate School of the Environment, Macquarie University, Sydney, NSW, 2109, Australia.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2010 Feb;196(2):147-54. doi: 10.1007/s00359-009-0501-0. Epub 2010 Jan 5.
Physiological stress responses to capture may be an indicator of welfare challenges induced by animal handling. Simultaneously, blood chemistry changes induced by stress responses may confound experimental design by interacting with the biological parameters being measured. Cortisol elevation is a common indicator of stress responses in mammals and reproductive condition can profoundly influence endocrine response. We measured changes in blood cortisol and testosterone induced by handling reproductively active male Weddell seals (Leptonychotes weddellii) early and late in the breeding season. Weddell seals have the highest resting cortisol levels of all mammals yet showed a clear, prolonged elevation in cortisol in response to capture. Responses were similar when first caught and when caught a second time, later in the breeding season. Baseline testosterone levels declined over the breeding season but were not altered by capture. Administering a light dose of diazepam significantly ameliorated the cortisol response of handled animals without affecting testosterone levels. This may be an effective way of reducing acute capture stress responses. Male breeding success in years males were handled was no different to the years they were not, despite the acute capture response, suggesting no long-term impact of handling on male reproductive output.
生理应激反应的捕获可能是福利挑战的指标所造成的动物处理。同时，血液化学变化引起的应激反应可能会通过与正在测量的生物参数相互作用而混淆实验设计。皮质醇升高是哺乳动物应激反应的常见指标，生殖状况可以深刻影响内分泌反应。我们测量了繁殖活跃的雄性威德尔海豹（Leptonychotes weddellii）在繁殖季节早期和晚期因处理而引起的血液皮质醇和睾丸激素的变化。威德尔海豹具有所有哺乳动物中最高的静息皮质醇水平，但在捕获时表现出明显的、持久的皮质醇升高。当第一次被捕和在繁殖季节后期第二次被捕时，反应是相似的。基础睾丸激素水平在繁殖季节下降，但不受捕获影响。给予小剂量的地西泮可显著改善处理动物的皮质醇反应，而不影响睾丸激素水平。这可能是减少急性捕获应激反应的有效方法。在处理过的雄性繁殖成功的年份与未处理的年份没有区别，尽管有急性捕获反应，但这表明处理对雄性生殖输出没有长期影响。
