Using a novel, high welfare in vivo feeding device for poultry red mite and its integration with other novel tools for this parasite

鸡舍感染家禽红螨（PRM）是世界范围内蛋业的一个主要动物福利和经济问题，无论采用哪种类型的产蛋系统。PRM对蛋鸡的影响主要有两方面：一是螨虫叮咬蛋鸡，取食蛋鸡血液导致蛋鸡过敏和贫血；二是螨虫传播疾病给蛋鸡造成间接影响。传统的在鸡舍里喷洒化学药剂来控制PRM的方法现在已经失效了，因为这些螨虫已经对化学药剂产生了抗药性。因此，对控制PRM的新方法的需求很高，世界各地的几个研究小组正在研究这些新的控制方法。通常情况下，对新型控制方法的测试首先在实验室测试中使用螨虫，然后使用大量母鸡进行现场测试。例如，控制PRM的疫苗的开发通常使用最初的实验室筛选试验来确定潜在的疫苗，然后再进入实地试验，每次试验可使用多达800只母鸡，持续数月。这种策略有两个主要缺点：1)基于实验室的分析结果是高度可变的，可能无法准确预测现场试验的结果；野外试验涉及大量鸟类长期暴露于寄生虫。为了解决这些问题，我们开发了一种“母鸡身上”的螨虫喂养装置，作为实验室测试的替代方法，它可以在进行实地研究之前更准确地评估疫苗和其他螨虫控制方法。该战略通过大大减少母鸡的使用数量，解决了3r原则的“减少”方面的问题，因为它将在疫苗或其他控制方法（例如新农药）进入田间试验之前准确地识别出效果不佳的疫苗或其他控制方法。这种对母鸡的系统也可用于在不持续将鸟类暴露于寄生虫的情况下，对少量母鸡（每个处理组4只，而不是现场试验中每个处理组400只）长期测试螨虫控制方法的有效性。因此，这解决了第二个3Rs原则-“细化”，因为它允许鸟类在绝大多数实验期间保持远离寄生虫，寄生虫每三周只在短时间内（3小时）接触鸟类，而不是在现场试验中遇到的持续暴露。我们已经通过成本行动流动补助金成功地将这项技术转让给西班牙卡斯蒂利亚-拉曼查大学的一个疫苗开发小组，我们现在希望举办一个为期3天的讲习班，通过实际演示和讨论如何将这项技术与其他新颖和新兴的PRM研究工具相结合，以促进其在整个欧洲实验室的采用。拟派参加讲习班的人员对改进和减少母鸡的使用感兴趣，因为它们可以用于开发新的干预措施，包括杀虫剂、驱虫剂和疫苗，以及研究PRM传播疾病的能力。该提案的主要目的是在Moredun研究所举办一个研讨会，以：1)展示一个优化系统的构建和使用，供科学家在进行大规模田间试验之前，用于精确、轻度严重和增强的新疫苗和杀虫剂的预筛选，以控制一种吸血寄生虫；2)演示和讨论如何将这项新技术与该领域的其他新兴技术相结合。每个被选中的参与者都是更大的网络的成员，有潜力利用这些技术，超出了最初的讲习班的范围。

Infestation of hen houses with poultry red mites (PRM) is a major animal welfare and economic problem for the egg industry worldwide, irrespective of the type of laying systems employed. The two main impacts of PRM on laying hens are direct effects of the mites biting the birds and feeding on their blood which causes irritation and anaemia, and indirect effects caused by the mites transmitting diseases to the hens. Traditional methods of controlling PRM with chemical sprays in hen houses are now failing as the mites become resistant to the chemicals. Demand for novel methods of controlling PRM is therefore high and several research groups around the world are working on these new methods of control. Typically, the testing of novel control methods uses mites in laboratory-based tests initially, followed by field testing using large numbers of hens. For example, the development of vaccines to control PRM routinely uses initial laboratory-screening tests to identify potential vaccines before moving into field trials which can use up to 800 hens in each trial and last for several months. This strategy has 2 major drawbacks:1) Results from the laboratory-based analyses are highly variable and may not accurately predict what happens in field trials;2) Field trials involve large numbers of birds continually exposed to parasites for prolonged periods.To address these issues we have developed an 'on-hen' mite feeding device, as an alternative to the laboratory-based tests, which allows much more accurate assessment of vaccines and other mite control methods on small numbers of hens before field studies are conducted. This strategy addresses the "Reduction" aspect of the 3Rs principles by greatly reducing the number of hens used, as it would accurately identify poorly performing vaccines or other control methods (e.g. new pesticides) before they were progressed to field trials. This on-hen system can also be used to test the effectiveness of mite control methods across prolonged periods on small numbers of hens (4 per treatment group, as opposed to 400 per treatment group in field trials) without continually exposing birds to the parasites. This therefore addresses a second 3Rs principle - "Refinement" as it allows the birds to remain free from the parasites for the vast majority of the experimental period, with parasites only accessing the birds for short (3 hour) periods every 3 weeks instead of the continual exposure encountered in field trials. We have successfully transferred this technology to a vaccine-development group at University of Castilla-La Mancha, Spain through a COST Action mobility grant and we now wish to hold a 3-day workshop to disseminate this technology with practical demonstrations and discussions around how it intersects with other novel and emerging tools for PRM research to promote its adoption in laboratories across Europe. The proposed participants in the workshop have interests in both refinement and reduction of the use of hens in the development of novel interventions including pesticides, repellents and vaccines and in investigations of the ability of PRM to spread disease. The principal aims of this proposal are to hold a workshop at Moredun Research Institute to:1) Demonstrate the construction and use of an optimised system for scientists to use in an accurate, mild-severity and enhanced pre-screening of new vaccines and pesticides for the control of a blood-feeding parasite before progressing to large field trials, and;2) Demonstrate and discuss how this novel technology may be integrated with other emerging technologies in this field.Each of the selected participants is a member of larger networks with the potential to exploit these technologies beyond the reach of this initial workshop.