The intake potential of silage is determined by the intrinsic characteristics of parent herbage, e.g. plant species, cell wall content and digestibility. Measured intake may, however, be markedly reduced due to modifications of carbohydrate and N fractions during ensilage, and therefore the relationship between digestibility and intake has been weaker for ensiled than dried forages. Increased proteolysis and extent of fermentation have generally decreased silage DM intake (SDMI). However, correlations between fermentation characteristics and SDMI reported in literature are generally weak, particularly those based on individual cows data. In addition to D-value (g DOM/kg DM) and fermentation quality, SDMI is also influenced by DM content, amount and type of concentrates fed, production level and stage of lactation. Gordon et al. (1998) measured SDMI under standardized conditions in cattle and developed straight NIRS calibrations for the prediction of SDMI. The purpose of this study was to develop a SDMI index describing the relative intake potential using available data based on mean treatment digestibility, fermentation characteristics and SDMI values.