Abstract:
Behaviour is often the fundamental driver of disease transmission, where behaviours of individuals can be seen to scale up to epidemiological patterns seen at the population level. Here we focus on animal behaviour, and its role in parasite transmission to track its knock-on consequences for parasitism, production and pollution. Livestock face a nutrition versus parasitism trade-off in grazing environments where faeces creates both a nutritional benefit, fertilizing the surrounding sward, but also a parasite risk from infective nematode larvae contaminating the sward. The grazing decisions of ruminants depend on the perceived costs and benefits of the trade-off, which depend on the variations in both environmental (e.g., amounts of faeces) and animal factors (e.g., physiological state). Such grazing decisions determine the intake of both nutrients and parasites, affecting livestock growth rates and production efficiency. This impacts on the greenhouse gas costs of ruminant livestock production via two main mechanisms: (1) slower growth results in longer durations on-farm and (2) parasitised animals produce more methane per unit food intake. However, the sensitivity of behaviour to host parasite state offers opportunities for early detection of parasitism and control. Remote monitoring technology such as accelerometers can detect parasite-induced sickness behaviours soon after exposure, before impacts on growth, and thus may be used for targeting individuals for early treatment. We conclude that livestock host x parasite interactions are at the centre of the global challenges of food security and climate change, and that understanding livestock behaviour can contribute to solving both.
摘要:
行为往往是疾病传播的根本驱动因素,可以看到个体的行为扩大到人口水平的流行病学模式。这里我们关注动物行为,以及它在寄生虫传播中的作用,以追踪其对寄生虫的连锁反应,生产和污染。牲畜在放牧环境中面临营养与寄生虫的权衡,在放牧环境中,粪便既能带来营养益处,给周围的草皮施肥,而且还有感染线虫幼虫污染草皮的寄生虫风险。反刍动物的放牧决定取决于权衡的感知成本和收益,这取决于两种环境的变化(例如,粪便的数量)和动物因素(例如,生理状态)。这种放牧决定决定了营养素和寄生虫的摄入量,影响牲畜生长速度和生产效率。这通过两个主要机制影响反刍动物牲畜生产的温室气体成本:(1)生长较慢导致农场持续时间更长;(2)寄生动物每单位食物摄入产生更多的甲烷。然而,行为对宿主寄生虫状态的敏感性为早期发现和控制寄生虫提供了机会。诸如加速度计之类的远程监控技术可以在暴露后不久检测到寄生虫引起的疾病行为,在对增长产生影响之前,因此可用于靶向个体进行早期治疗。我们得出的结论是,牲畜宿主x寄生虫相互作用是全球粮食安全和气候变化挑战的中心,了解牲畜行为有助于解决这两个问题。