Development of prevention and treatment strategies for parasites in poultryVeronikaMaurerauthorZivileAmslerauthorFelixHeckendornauthorErikaPerlerauthorParasitic infections are likely to be more important in organic and other free-range hens than in birds kept indoors. Several workpackages of QLIF aim at improving prevention and therapy of helminth (Ascaridia galli and Heterakis gallinarum) and arthropod (Dermanyssus gallinae) parasites of laying hens. This paper is a summary of the work undertaken in the first 3 years of QLIF. Poultry Health and welfare2007Conference paper, poster, etc.