Polyculture-livestock systems can use complementarities between crops and livestock to reduce their input consumption. In four French regions, expert meetings were organised to discuss the possible evolution of these systems under three contrasting forward-looking scenarios: “Ultra-liberalisation and galoping globalisation” (S1), “Territorial economy and focus on quality” (S2) and “Agri-ecological and energy transition” (S3) and to reflect on possible ways to support polyculture-livestock in each scenario. To support these discussions, the impacts of the structuring elements of the scenarios have been simulated using the ORFEE bioeconomic model for a typical crop/livestock farm in each region. The experts agreed that S1 would move towards a reduction in livestock farming and greater specialisation in arable crops, that S2 would be the most favourable for diversified systems, and that S3 would lead to a reduction in livestock farming, but greater integration between livestock and crops. The results of the simulations are in the same direction, except for milk production, which increases in S1 due to a forecast increase in the price of milk and an unlimited labour force. The simulations made it possible to calculate sustainability indicators: S1 is higher for economic indicators, S2 better for social indicators and S3 more environmentally friendly. The simulations also highlight the need to maintain livestock farming in an agro-ecological transition to reduce mineral fertilisers and pesticides.