Limits of the specialization of agriculture are widely documented in the scientific literature in terms of environmental, social and economic impacts. At the same time, ecological issues and agroecological transition of agri-food systems must be considered both at farm and territorial levels. Crop-livestock integration at both levels seems a promising avenue for building sustainable systems. In this study, we elaborate scenarios of agroecological transitions based on innovative crop-livestock synergies. We studied sheep integration into organic wines and cereals cropping systems in South-western France. We firstly assessed the technical potential for crop-livestock integration at a territorial level with a seasonal supply-demand model. Secondly, we designed acceptable future scenarios from real situation through a participative process and simulated them. These scenarios are related to climate change impact on resources, use of new fodder resources, and adaptation of animal requirements to fodder resources availability. Our results show that in heterogeneous landscape mosaic as it is the case here, sheep herds are fed with a wide range of resources, available in a complementary way throughout the seasons. Under climate change, current situation won’t be sustainable due to insufficient fodder resources at certain critical times (in summer specifically). However, additional resources at territorial scale (legume fodder, rangeland, vineyard inter-row) could be used at different seasons to maintain or even increase the number of sheep bred. Moreover, transhumance during summer could decrease animal needs when fodder resources are missing and transhumance during winter could increase the number of sheep bred when the demand for weed control in the vineyard is high. Finally, we discuss brakes and levers resulting from the analysis to assess to what extent and in what terms this innovative initiative draws a model of agroecological transition of farming systems at territorial level.