This research was carried out to validate the effectiveness of the Near-IR spectroscopy method in predicting intake and digestibility of DM and nutrients of diets for feedlot lambs, in order to compare with the conventional laboratory method. Samples of diets, ort,s and feces of forty Santa Ines lambs were subjected to both methods and analyzed for DM, MM, NDF, ADF, CP, and EE for future calculations for intake and digestibility. Most of the model's correlation coefficient was in the range of 0.66 to 0.81, being suitable for quantitative prediction. Highest values for CP content of 0.85 (diets) and 0.87 (orts) were observed. There were high correlations between the methods to predicting intake (average values of 0.93) and digestibility (average values of 0.93). Correlations between the variables obtained by the prediction of NIRS and the conventional method were adequate, showing that regardless of the method, the nutritional content of diets, orts and feces can be used to calculate the intake and digestibility of DM and nutrients of lambs’ diets. The Near-IR spectroscopy method is recommended for accuracy, speed and low cost compared to conventional method.
chemical composition; digestibility; intake; NIRS; ovine