Potential of Near-Infrared Reflectance Spectroscopy (NIRS) to Predict Nutrient Composition of Bromus tomentellus

Document Type : Research and Full Length Article


1 Faculty of Natural Resources, University of Tehran

2 Range Management, From Natural Resources Faculty University of Tehran

3 Department of Natural Resources, University of Urmia


Determination of forage quality of available species is one of the fundamental
factors for the management of rangelands. Near-Infrared Reflectance Spectroscopy (NIRS)
was used to analysis 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 prediction 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%) for
N, ADF, DMD and ME, respectively. The results obtained from this study indicated that
NIRS had a potentiality to be used in predict the N, ADF, and the estimated DMD and ME
of forage samples content.