Calls for antimicrobial use (AMU) reduction in farms are growing. It is yet challenging for farmers to reduce AMU without reducing their economic performances. This paper proposes an original bio-economic framework for AMU management in French dairy farms. This framework combines a recursive economic optimization model with a biologic model that describes the effects of health management strategies on the dynamic of a dairy herd. An appealing feature of the newly developed model is that it allows testing win-win strategies in terms of health management: maximising risk-adjusted revenue while minimising AMU and workload. It can also be used to test incentives to encourage farmers to adopt virtuous strategies and practices. In the present paper, the bio-economic model is applied mainly to mastitis management, which represents the first reason for AMU in dairy production. The results identified selective dry-off strategy (dry-off with AM for at risk cows only) rather than the conventional systematic dry-off strategy (AM on all cows at dry-off) as being effective to lower AMU while maintaining famer’s income.