Sixteen adult sheep fed on different proportions of barley grain and straw (60:40, 45:55, 30: 70 and 15:85) were used to obtain regression equations for prediction of dry matter (DMI) and digestible organic matter (DOMI) intake, dry matter (DMD), organic matter (OMD), crude protein (CPD) and neutral detergent fibre (NDFD) digestibility, and proportion of straw consumed (% straw) from the NIRS analysis of the faeces. All equations had coefficients of determination in calibration higher than 0.65, except that for the prediction of NDFD (R² = 0.11). The coefficients of determination in cross-validation were much lower, with only DMD, OMD and % straw predictions showing values higher than 0.70.