Prediction of forage quality parameters in some range species by near infrared reflectance spectroscopy

Determination of grazing capacity in rangelands is an important factor for livestock husbandry. Improved forage quality is an important goal for improving animal performance. The aim of this study was to assess near infrared reflectance spectroscopy (NIR) as a rapid and reliable method for estimating quality parameters in nine range species as three grasses Bromus tomentellus، Agropyron intermedium and Dactylis glomerata، three forbs Achillea millefolium، Coronilla varia، Centaurea virgata and three shrubs Scariola orientalis، Artemisia aucheri and Thymus kotschyanus. NIR calibrations were derived for crude protein (CP)، dry matter digestibility (DMD) and acid detergent fiber (ADF). To maximize variability of samples for analysis، were collected at three phenological stages as initiated growth، full flowering and seed ripening in ranges of central Alborz (Taleghan). Samples were dried and grinded using standard laboratory methods. A sub samples were analyzed using standard laboratory chemical procedures to estimate CP، DMD، ADF and total ash. The other sub samples were scanned by means of a 20-filter set of the Inframatic8620. NIR spectra were recorded for each sample. A separate independent set was used for predictions. The calibrations obtained from this study had a high level of accuracy based on coefficient of determination (R2)، standard errors of calibration (SEC) and standard errors prediction (SEP). SEC were ranged from (0. 15 to 1. 09)، (0. 21 to 0. 86)، (0. 83 to 3. 94) and (0. 52 to 4. 96) and SEP were ranged from (0. 13 to 0. 75)، (0. 17 to 0. 61)، (0. 62 to 3. 34) and (0. 31 to 3. 84) for CP، Ash، DMD and ADF، respectively. The correlation values between laboratory data and NIR prediction was very high for all traits in particular for CP. The results confirm that NIR can use a rapid، precise and cost effective method for measurement quality traits in range species.