In this study the accuracy of several prediction equations for voluntary roughage intake was analysed. The validity was based on automatically recorded feed intake data from 82 cows kept under different feeding strategies. The main results can be summarized as follows: -The prediction equations for roughage intake of for first lactation and of for all lactations show the lowest mean square error terms (4.39 and 7.12 kg-2 DM) with a bias-2 of 0.24+ and 1.3-kg-2 DM, respectively. -The equations for cows fed a total mixed ration led to a higher accuracy. -There is no difference in the precision whether roughage intake or total intake is predicted. -Some of the equations are valuable to estimate the mean intake of the herd. On the other hand there is a low reliability predicting the dry matter intake of the single cow.