The problem of antimicrobial resistance is now recognised as a One Health issue (human, animal and ecosystem health) and many public and partly state-controlled actors are therefore contributing towards the ways antibiotics are regulated in livestock farming. These regulatory issues, and sometimes controversies, take place at international, regional and local levels regarding the way the measures against antimicrobial resistance are defined. Our projects seek to analyse how these policies are constructed and implemented at these differents scales and how the balance of power between different actors (States, international organisations, expertise agencies, etc.) influence the way the problem of antimicrobial resistance is dealt with.