The PPILOW project aims to co-construct innovations to improve Poultry and Pig Welfare in Low-input outdoor and Organic farming systems through a multi-actor approach. Its first step was to sum up animal welfare challenges observed in these systems and levers of improvement, from a review of literature data and research projects. Data were completed with information from key informants of the supply chains of poultry meat, eggs and pork in Italy, France, the United Kingdom and Finland. The interviews indicated that the main issues in poultry were: feeding, biosecurity, lack of range use and range management, feather pecking, weather, regulation, flock size or density, predation, bone fractures, lack of robustness, parasitism, pododermatitis, arthrosis, nervousness, water quality, catching and time spent by farmers. The main issues in pig were: feeding, tail biting, mortality, weather, predation, lack of robustness, lack of range use, castration, animal aggressiveness and competition, water quality, range management, human welfare, biosecurity issues, flock size or density, parasitism, insolation burns, joint abnormalities, parturition in freedom and pollution. This information has implemented a participatory approach for proposing welfare-improvement levers. Some issues and potential solutions were included in PPILOW experiments (phytotherapy against parasitism, involvement of animal personality in range use, rearing of entire pig males, genetic selection for reduced piglet mortality, improved farrowing huts for sows and piglets reared on range, avoiding feather pecking in laying hens with intact beaks, avoiding the killing of day-old male chicks, etc.), and solution costs evaluated. The results will provide a combination of practical solutions for welfare improvement in Europe. The PPILOW project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement N°816172.