Agricultural energy consumption is an important economic, environmental and social issue. The French national project EDEN aims at the analysis of energies consummations for two main activities: Agricultural productions and dairy activities using OLAP systems. In this paper, we focus on energetic assessment of dairy activities. We present a multidimensional model allowing for monitoring of energies used for dairy activities. The developed model is complex but in counterpart it allows for analysis of inputs, outputs and their relations of the dairy farm system. In this way decision-makers can understand and correlate energetic trends overall the global production process.