INTRODUCTION AND OBJECTIVE PPILOW is a multiactor project aiming to co-create with end-users innovations for improving the welfare of pigs and poultry in low-input outdoor and organic farming systems. The PPILOW participatory approach involves National Practitioner Groups (NPG) in co-building innovative breeding and rearing strategies and techniques on this purpose. Firstly, the project gathers a comprehensive inventory of the ethical, socio-economic and technical factors that are essential to improve poultry and pig welfare in organic and low-input outdoor production systems, providing a shortlist of potential levers of improvement that are experimentally- and on-farm-tested within the project. The NPGs also co-build and test with PPILOW partners mobile applications for assessing and benchmarking animal welfare status on-farm, and tools for evaluating the sustainability of the tested lever based on the One Welfare concept. METHODS AND RESULTS PPILOW partners organized the participatory approach by setting-up nine NPG dedicated to pig or poultry in six countries. The NPG identified barriers to welfare and levers for improvement, and co-created with partners shared tools and strategies for improving animal welfare to be tested experimentally and on-field. Standardized mobile apps for farmers to self-assess and benchmark on-farm the welfare status of the animals were co-developed (PIGLOW® for pigs) or refined (EBENE® for poultry) with NPG, and made EU-freely available in 9 and 7 European languages, respectively. They are currently being evaluated in longitudinal on-farm studies. Meanwhile, the creation of a data collection framework based on the One Welfare approach centred on both human and animal welfare has been co-created with NPGs. The first experimental strategy focuses on enrichments allowing keeping laying hens and fattening pigs in organic and low-input systems without beak trimming and castration, currently applied to prevent feather pecking and boar taint in meat in laying hens and in pigs, respectively. Studies on alternatives, on the one hand to beak trimming using innovative incubation and insect larvae enrichment in laying hens, and on the other hand to piglet castration through the rearing of entire male pigs with enrichments, have been completed and are currently analyzed. The second strategy explores two strategies for avoiding killing day-old layer male chicks: raising dual-purpose breeds for both egg and meat productions and developing a new in ovo sexing method. Three experimental trials are comparing dual-purpose genotypes in three countries. The ones completed on both males and females showed a high variability of technical performance between genotypes, due to different strategy for crosses, exhibiting less or high layer or meat potentials, and the egg quality results for the different crosses were assessed. On-farm trials have started for enabling the multicriteria evaluation of the use of male genotypes, and the field studies on females have been engaged with voluntary NPG participants. Concerning in-ovo sexing, refinements on methodologies for electrophysical sensing are currently running. The PPILOW project also aims to propose innovative solutions for favouring positive behaviours, health and robustness through an increased adaptation to organic and outdoor systems for laying hens, slow-growing broilers and pigs. Studies with different broiler genotypes have allowed a better understanding of the determinants of exploratory behaviour, showing that ranging behaviour is stable over time and that high-ranging broilers are more prone to work for food than low-rangers. Early management levers for improving resilience are also currently tested, including the experimental use of temperature variations during incubation, and the set-up of on-farm hatching trials with NPG members. Partners working with layers and pigs are developing strategies to limit intestinal parasitic and bacterial infections through different feed supplements, based both on in vitro and in vivo studies. In infected layers, the effect of a feed based on fermented products has been tested. Microbiological, immunological and parasitic profiles were obtained in pigs, and in vitro methods for the screening of plant extracts have been established, showing the high potential of some plants to limit worm infections. Joint protocols are developed and implemented to improve sow welfare and piglet survival through selective breeding and an innovative farrowing house design for outdoor rearing of sows and piglets. These innovative devices are currently tested in pig NPG members’ farms, with a close follow-up by NPG facilitator partners. The most promising PPILOW strategies are evaluated through multicriteria analyses according to the One Welfare concept, and business models are developed. CONCLUSIONS AND IMPLICATIONS Promising results of the project on the limitation of feather pecking in laying hens and aggressive behaviour in non-castrated pigs, of parasite development from pigs reared in low-input farms by the use of plant extracts, and for favouring piglet survival are currently obtained, which could help limiting the use of veterinary products, not only in low-input and organic farms, but also in conventional farms. Ultimately, the PPILOW project will also bring data on the feasibility of using such levers of improvement of pig and poultry health and welfare, and human well-being within the scope of the One Welfare concept. The project PPILOW has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N°816172.