Co-definition and evaluation of sustainable beef farming systems based on resources non edible by humansDue to a growing world population and changing consumption patterns, demand for animal products is expected to increase. Ruminant-based systems have the potential advantage of using resources non edible by humans and converting these into high quality human food. However, the emergence of intensive ruminant production systems, relying on increasing use of concentrate feeds, with food value, and the related increase in land abandonment in traditional grassland regions, has increased scrutiny in respect of the sustainability of EU livestock productions. Moreover the consumers’ point of view, the social acceptability of cattle products is being questioned with regards to food quality and safety, animal welfare and the competition between feed and food. To face these drawbacks, we hypothesize that cattle farming systems which rely mainly on grasslands and agro-industrial resources non-edible by humans are more or can be designed to be more sustainable than specialized systems which use feedstuffs that could also be directly used as food or that was produced at the detriment of food production. In addition such systems would greatly contribute to circular economy. Our measure of sustainability includes, environmental and social dimensions as well as economic perspectives taking into account the services delivered by these systems. Our proposal focuses on beef production systems as they are increasingly questioned by society. To test this, actual and potential performances of systems representative of Europe will be compared, mobilizing multidisciplinary and multi-actors approaches to co-define 1-beef system types, 2-the set of sustainability indicators to be mobilized, 3-potential scenarios of evolution for more sustainable systems. These scenarios will be evaluated and, furthermore, suitable incentive measures to enhance their implementation will be tested and, when relevant, proposed. The dissemination of results will be facilitated throughout this bottom-up approach.