This paper presents an analysis of the consequences, for French farms, of the decisions made under the CAP Health Check by the Minister of Agriculture. Simulations were carried out thanks to the Farm Accountancy Data Network (FADN) and Network Livestock of the Institut de l'Elevage. They can, under certain assumptions of implementation, assess the economic impact of measures adopted in February 2009 (in terms of variation in farm income and direct payments) and discuss their effects on the dynamics of herbivorous productions. According to this work, the reorientation of supports will be favourable for grazing livestock farms, mainly those with a high proportion of grassland in agricultural land. It will, however, be economically disadvantageous for farm crops and intensively reared cattle. The redistribution of direct aid induced a transfer from regions located in the north of the Loire to those located in the south (especially in the mountains and areas with high proportions of grassland). The shift in support among the productive sectors, which was modest but highly significant, was aimed at enhancing their legitimacy by linking them more clearly to the remuneration of environmental and territorial services.