Improving sustainable parasite control in British dairy cattle

从一个健康的角度来看，开发提供信息和促进可持续寄生虫控制的工具是一项优先事项。这项研究旨在提高对英国奶牛寄生虫病的了解，以及在控制寄生虫感染的范围内对动物健康、生产和食品安全的了解。然后，该项目将开发和评估工具，以促进可持续的寄生虫控制，减少对抗寄生虫药物的依赖及其相关问题，如耐药性、公共卫生和环境。通过与英国国家牛奶记录机构的合作，将利用现有的牛奶记录数据和一份简短的调查问卷，收集其现有客户(约40%的英国奶牛场)有关生产记录、放牧实践和寄生虫控制策略的信息。这使得能够识别放牧哺乳奶牛的农场，以进行随后的血清阳性分析和寄生虫感染的牛群水平因素。血清阳性率估计将通过散装罐装牛奶(BTM)样本测试在英国范围内获得。寄生虫特异性抗体酶联免疫吸附试验将被用来确定牛群水平对奥斯特塔吉、肝片吸虫和胎盘毛滴虫的暴露，据估计，这些疾病每年给英国奶牛业造成的损失超过1.47亿GB(Charlier等人，2020年)。将在2024-2025年放牧季节利用纵向抽样提供每种寄生虫的英国时空分布，并进行进一步的有针对性的测试，以评估和验证下文开发的疾病风险预测模型。血清阳性率的同时分析使人们有机会确定感染风险期的相对丰度和时间。据估计，气候变暖已经影响了一些寄生虫物种的地理分布和季节丰度，这可能会导致寄生虫感染的季节性风险出现意想不到的差异(Veneer，2020)。疾病风险预测模型的使用可以构成可持续寄生虫控制计划的一部分。收集的血清阳性率数据随后将用于评估、开发和验证每种寄生虫的现有基于气象的机械性疾病风险预测模型，目的是确定这些模型是否可用于确定有针对性的诊断测试和治疗使用的风险期。这一假设将在2026年的放牧季节在候选农场进行测试。为了量化蠕虫病对动物生产力的影响，将探索血清阳性率和核磁共振健康数据之间的关系，以确定并进一步细化有针对性的测试和治疗，以达到个人水平。随后，将与纽卡斯尔大学合作，通过农场药物使用和牛奶残留检测进一步探索这些关系，以了解抗寄生虫使用对食品安全、食物链污染和环境影响的风险。将评估本研究假设的拟议发展、干预措施和工具是否可以通过允许在高风险时期进行更有重点的测试来提高残留检测战略的敏感性。据推测，这项研究将提高对英国奶牛寄生虫病的了解，并量化这一疾病对公共、环境和动物健康的影响。此外，假设这项研究将开发疾病风险预测模型，以确定风险时期，并为可持续的寄生虫控制做出贡献。参考文献：Charlier等人。(2020)。Doi:https://doi.org/10.1016/j.prevetmed.2020.105103.Vineer，H.(2020)。Doi:https://doi.org/10.1016/j.cvfa.2019.11.002.

The development of tools to inform and promote sustainable parasite control is a priority from a One Health perspective. This study aims to improve the understanding of parasitic diseases in British dairy cattle and of animal health, production and food safety within the scope of controlling parasitic infections. This project will then develop and assess tools to promote sustainable parasite control, reducing reliance on antiparasitics and their associated concerns such as drug resistance, public health and the environment. Through collaboration with UK National Milk Records (NMR), information will be gathered of their existing clients (~40% of British dairy farms) relating to production records, grazing practices and parasite control strategies through the use of existing milk recording data and a brief questionnaire. This allows identification of farms that graze lactating dairy cattle for subsequent seroprevalence analysis and herd level factors of parasitic infection. Seroprevalence estimates will be obtained UK-wide via bulk tank milk (BTM) sample testing. Parasite-specific antibody ELISA's will be used to determine herd-level exposure to Ostertagia ostertagi, Fasciola hepatica and Dictyocaulus viviparus which are estimated to cost the UK dairy industry in excess of £147 million annually (Charlier et al., 2020). Longitudinal sampling will be utilised during the 2024-2025 grazing season to provide UK spatio-temporal distribution for each parasite, with further targeted testing to assess and validate disease risk forecasting models developed below. Concurrent analysis of seroprevalence allows opportunity to determine relative abundance and timing of infection risk periods. Climate warming is estimated to have already impacted the geographic distribution and seasonal abundance of some parasite species, which could result in an unexpected difference in seasonal risk of parasitic infection (Veneer, 2020). The use of disease-risk forecasting models can form part of a sustainable parasite control plan. Seroprevalence data collected will subsequently by used to assess, develop and validate existing meteorological-based mechanistic disease risk forecasting models for each parasite with the aim of identifying whether these models may be used to determine risk periods for targeted diagnostic testing and therapeutics use. This hypothesis will then be tested on candidate farms in the 2026 grazing season.To quantify the impact of helminthiasis on animal productivity, the relationships between seroprevalence and NMR health data will be explored to identify and further refine targeted testing and treatments to the individual level. In collaboration with Newcastle University, these relationships will then be further explored with on-farm pharmaceutical usage and milk residue testing to provide an understanding of the risk to food safety, food chain contamination and environmental implications of antiparasitic use. It will be assessed whether the proposed developments, interventions and tools postulated by this study may improve the sensitivity of residue testing strategies by allowing more focused testing during high risk periods. It is hypothesised that this study will improve the understanding of parasitic disease in British dairy cattle and quantify the impacts of this on both public, environmental and animal health. Moreover, it is hypothesised that this study will develop disease risk forecasting models to identify periods of risk and contribute to sustainable parasite control. References:Charlier et al. (2020). doi:https://doi.org/10.1016/j.prevetmed.2020.105103.Vineer, H. (2020). doi:https://doi.org/10.1016/j.cvfa.2019.11.002.