Abstract
We developed a method for measuring the concentration of volatile basic nitrogen (VBN) in aqueous extract of silage using near-infrared reflectance spectroscopy (NIRS). With 532 samples of silages, the high-resolution NIRS-calibration curve was obtained in the conditions as follows; using a transmitted light spectrum by 1mm path length; using the second derivative spectrum by segment size of 40nm; partial least squares regression analysis was used to make NIRS-calibration; the wavelength region were 1600-1800 and 2100-2350nm. Under these conditions, VBN concentrations could be predicted with a relatively high accuracy; determination coefficient was 0.964, standard error of prediction (SEP) was 19.5, Evaluation Index was 7.2 and ratio of standard deviation of reference data in prediction sample to SEP was 6.6.
