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

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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.