ABSTRACT

There are an estimated half-a-million Plains Bison (Bison bison) present in North America in commercial and conservation herds. Most bison are rounded up and “worked” annually for parasite control, veterinarian attention, and processing, making it important to understand the impacts of these operations. Research indicates bison generally experience higher levels of stress than cattle during similar handling processes. However, most methods for assessing stress-level during working are invasive, increase handling time, and paradoxically increase stress levels. We designed a behavioral index to assess bison stress level during handling and used it to evaluate various predictors of stress response in a semi-wild bison herd. We examined how sex, age, herd of origin, previous experience, calf rearing, and body condition influenced bison stress response during working operations from 2015 to 2017. Our results indicate that stress level decreased with age and previous experience being worked through a particular facility. Additionally, herd of origin influenced stress level, indicating that stress response may have a genetic or epigenetic component. Our study provides an easily applicable tool for monitoring bison stress levels.

摘要

估计有 50 万头平原野牛 ( Bison bison) 存在于北美的商业和保护畜群中。大多数野牛每年都会被围捕并“工作”以进行寄生虫控制、兽医关注和处理，因此了解这些操作的影响非常重要。研究表明，在类似的处理过程中，野牛通常比牛承受更高水平的压力。然而，在工作期间评估压力水平的大多数方法都是侵入性的，增加了处理时间，并且自相矛盾地增加了压力水平。我们设计了一个行为指数来评估处理过程中的野牛压力水平，并用它来评估半野生野牛群中压力反应的各种预测因子。我们研究了 2015 年至 2017 年工作期间的性别、年龄、原产地、以前的经验、犊牛饲养和身体状况如何影响野牛的应激反应。我们的结果表明，压力水平随着年龄和以前在特定设施工作的经验而降低。此外，原产地影响压力水平，表明压力反应可能具有遗传或表观遗传成分。我们的研究为监测野牛压力水平提供了一种易于应用的工具。