The aim of this communication is to summarize a collective, interdisciplinary vision of the advances in knowledge needed, at different scales, to contribute to the transformation of livestock systems with health and welfare at the core while considering the other components of sustainability. We emphasize the need to consider health in a broader perspective and to deepen the question of positive emotional experiences regarding welfare while presenting positive interactions and some conflicts between the two. Ex. when improving welfare by providing a more stimulating environment such as outdoor access the risk of infectious disease may increase. Jointly improving health and welfare of animals raises different questions along the production chain. At the animal level: longterm links between better welfare and physiological balance, the role of microbiota, the psycho-neuro-endocrine mechanisms linking positive mental state and health, and the trade-off between the physiological functions of production, reproduction and immunity should be explored. At the farm level, in addition to studying the relationships at the group level between welfare, health and production, we support the idea of co-constructing innovative systems with livestock farmers, as well as analyzing the cost, the acceptability and the impact of improved systems on their working conditions and well-being. At the production chain or territory levels questions include: studying the best strategies to improve animal health and welfare while preserving economic viability, labelling of products and consumers’ willingness to pay, the consequences of heterogeneity in animal traits on the processing of animal products, the spatial distribution of livestock farming and the organization of the production and value chain. Citizens’ knowledge of livestock farming should be improved and more constructive exchanges between breeders, livestock professionals and citizens developed. We emphasise a interdisciplinary and transdisciplinary approach, involving all stakeholders, including public decision-makers, in a participatory research process. Note: our numerous co-authors will be acknowledged during the presentation