Gastrointestinal nematodes are a significant threat to the economic and environmental sustainability of keeping livestock, as adequate control becomes increasingly difficult due to the development of anthelmintic resistance in some systems and climate-driven changes to infection dynamics. To mitigate any negative impacts of climate on gastrointestinal nematode epidemiology and slow anthelmintic resistance development, there is a need to develop effective, targeted control strategies that minimise the unnecessary use of anthelmintic drugs and incorporate alternative strategies such as vaccination and evasive grazing. However, the impacts climate and gastrointestinal nematode epidemiology may have on the optimal control strategy are generally not considered, due to lack of available evidence to drive recommendations. Parasite transmission models can support control strategy evaluation to target field trials, thus reducing the resources and lead-time required to develop evidence-based control recommendations incorporating climate stochasticity. Gastrointestinal nematode population dynamics arising from natural infections have been difficult to replicate and model applications have often focussed on the free-living stages. A flexible framework is presented for the parasitic phase of gastrointestinal nematodes, GLOWORM-PARA, which complements an existing model of the free-living stages, GLOWORM-FL. Longitudinal parasitological data for two species that are of major economic importance in cattle, Ostertagia ostertagi and Cooperia oncophora, were obtained from seven cattle farms in Belgium for model validation. The framework replicated the observed seasonal dynamics of infection in cattle on these farms and overall, there was no evidence of systematic under- or over-prediction of faecal egg counts. However, the model under-predicted the faecal egg counts observed on one farm with very young calves, highlighting potential areas of uncertainty that may need further investigation if the model is to be applied to young livestock. The model could be used to drive further research into alternative parasite control strategies such as vaccine development and novel treatment approaches, and to understand gastrointestinal nematode epidemiology under changing climate and host management.

中文翻译：

---

GLOWORM-PARA：一个灵活的框架，用于模拟感染放牧牲畜的胃肠道线虫寄生相的种群动态。

胃肠道线虫对饲养牲畜的经济和环境可持续性构成重大威胁，因为由于某些系统中驱虫抗药性的发展以及气候驱动的感染动态变化，进行适当控制变得越来越困难。为了减轻气候对胃肠道线虫流行病学的不利影响和缓慢的驱虫药耐药性发展，需要制定有效的，有针对性的控制策略，以最大程度地减少驱虫药的不必要使用，并纳入疫苗接种和逃避放牧等替代策略。但是，由于缺乏可用的证据来推动推荐，因此通常不考虑气候和胃肠道线虫流行病学对最佳控制策略的影响。寄生虫传播模型可以支持针对目标田间试验的控制策略评估，从而减少了开发包含气候随机性的基于证据的控制建议所需的资源和前置时间。由自然感染引起的胃肠道线虫种群动态很难复制，模型应用通常集中于自由生活阶段。提出了针对胃肠线虫寄生期GLOWORM-PARA的灵活框架，该框架补充了自由生存阶段的现有模型GLOWORM-FL。从比利时的七个养牛场获得了在牛中具有重要经济意义的两个物种的纵向寄生虫学数据，即Ostertagia ostertagi和Cooperia oncophora。该框架复制了在这些农场上观察到的牛感染的季节性动态，总体而言，没有证据表明系统地低估或高估了粪便卵数。但是，该模型低估了在一个犊牛非常年轻的农场上观察到的粪便卵数，从而突出了潜在的不确定性区域，如果将该模型应用于幼小的牲畜，可能需要进一步研究。该模型可用于推动对替代寄生虫控制策略（如疫苗开发和新型治疗方法）的进一步研究，并了解气候变化和宿主管理下的胃肠道线虫流行病学。该模型低估了在一个犊牛非常年轻的农场上观察到的粪便卵数，从而突出了潜在的不确定性区域，如果将该模型应用于幼小的牲畜，可能需要进一步调查。该模型可用于推动对替代寄生虫控制策略（如疫苗开发和新型治疗方法）的进一步研究，并了解气候变化和宿主管理下的胃肠道线虫流行病学。该模型低估了在一个犊牛非常年轻的农场上观察到的粪便卵数，从而突出了潜在的不确定性区域，如果将该模型应用于幼小的牲畜，可能需要进一步调查。该模型可用于推动对替代寄生虫控制策略（如疫苗开发和新型治疗方法）的进一步研究，并了解气候变化和宿主管理下的胃肠道线虫流行病学。