Sustainable control of helminths in dairy cattle - understanding processes leading to improved productivity

寄生性蠕虫对动物健康、福利和生产力有重大影响，占全世界农场动物疾病的50%以上。这对农民和企业都有巨大的经济成本，包括治疗成本、生产力损失，在严重情况下还会损失牲畜。乳制品行业目前的控制方法包括全面使用驱虫药，通常在缺乏诊断数据的情况下。治疗通常针对幼畜，人们认为一旦动物进入挤奶牛群，它们就获得了足够的免疫力来抵抗感染。新的倾倒大环内酯的引入，具有零撤奶期，延长了治疗窗口。坊间传闻称，这种治疗会在短期内增加产量，导致近年来这些驱虫剂的使用增加。这些声称还没有得到适当的量化，特别是在高产动物身上。因此，有必要评估驱虫剂的使用，就其使用提供建议，以免加速或鼓励驱虫剂耐药性的发展。该项目旨在验证这样一种假设，即对奶牛进行驱虫治疗会提高牛奶的产量和质量。这个项目将利用来自高产、有机和常规奶牛群的队列，产生实验数据和模型模拟，以进一步了解这些变化背后的潜在机制。和毛圆线虫(Trichostrong ylus spp.)都是有意义的。由于线虫卵的形态相似，目前鉴定感染动物和形成线虫种群的方法敏感性和特异性较低。作为欧盟一个主要财团的合作伙伴，利物浦大学与柏林自由大学建立了联系，后者开发了一种基于Luminex的新检测方法，用于检测牛奶中影响牛的五种蠕虫的特定抗体。我们将开发、优化和验证适用于英国环境的多重聚合酶链式反应(MT-PCR)，以确定感染每种动物的物种组合。

Parasitic helminths have a major impact on animal health, welfare and productivity accounting for over 50% farm animal disease worldwide. This has a great economic cost for both farmer and industry, through cost of treatment, loss of productivity and in severe cases, loss of livestock.Current control methods within the dairy industry include the blanket use of anthelmintic drugs, often in the absence of diagnostic data. Treatment is usually aimed at young stock, it is assumed that once animals enter the milking herd they have acquired sufficient immunity to resist infection. The introduction of new pour-on macrocyclic lactones that have zero milk withdrawal period, prolong the window for treatment. Anecdotal claims that this treatment results in short-term increases in yield, have led to an increased use of these anthelmintics in recent years. These claims that have not been properly quantified, especially in high yielding animals. Therefore there is a need to evaluate the use of anthelmintics, to provide advice on their use so as not to accelerate or encourage the development of anthelmintic resistance. The project aims to test the hypothesis that anthelmintic treatment of milking cows results in improved milk yield and quality. Using cohorts from high-yielding, organic and conventional dairy herds, this project will produce experimental data and model simulations to further our understanding of the underlying mechanisms behind these changes.Amongst the several species of parasitic helminths, Fasciola hepatica, Dictyocaulus viviparus, Ostertagia ostertagi, Cooperia spp. and Trichostrongylus spp. are of interest. Current methods for identifying infected animals and speciating nematode populations have low sensitivity and specificity due to the morphological similarity in nematode eggs. As a partner in a major EU consortium, University of Liverpool has links with Free University of Berlin, who have developed a new Luminex based assay to detect specific antibodies in milk to five species of helminth affecting cattle. We will develop, optimise and validate a multiplex PCR (MT-PCR) for a UK setting, to define the species mix infecting each animal.