The prediction of forage maize digestibility by near infrared reflection spectroscopy
DOI:
https://doi.org/10.18174/njas.v42i2.603Abstract
The potential of near infrared reflectance spectroscopy (NIRS) to predict organic matter digestibility (OMD) of fresh forage maize was examined. Cellulose digestibility, corrected to in vivo level, served as a reference method. Calibration was based on 261 samples, varying in OMD from 68.0 to 80.3% and validation occurred in 58 samples (71.7-75.9% OMD). With a scanning IA-500 monochromator the best equation, based on the second derivative of the reflected energy at wavelengths 1620 and 1664 nm, had a standard error of prediction (SEP) of 0.65%. The repeatability of the prediction amounted to 0.49% and was smaller than that of the reference analysis. The best equation, developed for a simulation of an IA-450 filter-apparatus, had a SEP of 0.74%. Cross-validation on the calibration set showed the validity of the calibrations for a wide range of digestibility. NIRS-predicted OMD was highly correlated with the reference OMD, whereas calculated OMD, based on constant digestion coefficients for the ears and stalk + leaves, did not show any relationship.Downloads
Published
1994-06-01
Issue
Section
Papers