Potential of near-infrared reflectance spectroscopy (NIRS) to predict nutrient composition of Bromus tomentellus

摘要

Near-infrared reflectance spectroscopy (NIRS) was used to analyse the nitrogen (N), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME) content of three phenological stages (vegetative, flowering and seeding) of Bromus tomentellus samples in grazing pastures of Iran. The sample set consisted of 40 samples for calibration and 23 samples for validation was used to predict N, ADF, DMD and ME, separately. The samples were measured by reflectance NIR in a 950-1650 nm range. Calibration models between chemical data and NIR spectra were produced using the method of partial least squares (PLS). The coefficients of determination (R2) and standard error of cross validation (SECV) were 0.94 (SECV: 0.208%), 0.98 (SECV: 1.76%), 0.98 (SECV: 1.97%), and 0.97 (SECV: 0.34) forN, ADF, DMD and ME, respectively. The results obtained from this study indicate that NIRS have a potential to be used to predict the N, ADF, and the estimated DMD and ME content of forage samples.