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

寄生虫对动物健康、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。这对农民和工业都造成了巨大的经济损失，包括治疗费用、生产力损失，在严重情况下还造成牲畜损失。乳制品行业目前的控制方法包括在缺乏诊断数据的情况下，全面使用驱虫药。治疗通常针对幼畜，假设一旦动物进入挤奶群，它们已经获得足够的免疫力来抵抗感染。引入新的大环内酯，有零停乳期，延长窗口的治疗。坊间声称，这种处理能在短期内提高产量，这导致近年来这些驱虫剂的使用增加。这些说法还没有得到适当的量化，特别是在高产动物中。因此，有必要对驱虫药的使用进行评价，并就其使用提供建议，以免加速或鼓励驱虫药耐药性的发展。该项目旨在验证对奶牛进行驱虫药治疗可以提高产奶量和质量的假设。通过对高产、有机和传统奶牛群的研究，该项目将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。在几种寄生蠕虫中，肝片吸虫、胎生蝶叶虫、Ostertagia ostertagi、Cooperia spp.和Trichostrongylus spp.是值得关注的。由于线虫卵的形态相似性，目前鉴定受感染动物和确定线虫种群的方法灵敏度和特异性较低。作为一个主要欧盟联盟的合作伙伴，利物浦大学与柏林自由大学建立了联系，后者开发了一种新的基于Luminex的检测方法，可以检测牛奶中针对影响牛的五种寄生虫的特定抗体。我们将为英国开发、优化和验证多重PCR (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.