Prediction of the Nutritive Value of Pasture Silage by Near Infrared Spectroscopy (NIRS)

Ernesto A. Restaino1, Enrique G. Fernández1, Alejandro La Manna1, and Daniel Cozzolino2*
The aim of this study was to investigate the use of near infrared reflectance (NIRS) spectroscopy to predict the nutritive value of silages from pastures and to assess the effect of silage structure type (e.g. bunker and bag silos) on the NIRS predictions. Samples (n = 120) were sourced from commercial farms and analyzed in a NIRS monochromator instrument (NIR Systems, Silver Spring, Maryland, USA) using wavelengths between 400 and 2500 nm in reflectance. Calibration models were developed between chemical and NIRS spectral data using partial least squares (PLS) regression. The coefficients of determination in calibration (R2) and the standard error in cross validation (SECV) were 0.73 (SECV: 1.2%), 0.81 (SECV: 2.0%), 0.75 (SECV: 6.6%), 0.80 (SECV: 6.7%), 0.80 (SECV: 4.0%), 0.60 (SECV: 3.6%) and 0.70 (SECV: 0.34) for ash, crude protein (CP), neutral detergent fiber (NDF), dry matter (DM), acid detergent fiber (ADF), in vitro dry matter digestibility (IVDMD) and pH, respectively. The results showed the potential of NIRS to analyze DM, ADF and CP in silage samples from pastures.
Keywords: silage, nutritive value, near infrared reflectance spectroscopy, pastures
1Instituto Nacional de Investigación Agropecuaria INIA La Estanzuela, Estación Experimental Alberto Boerger, Ruta 50, km 12, Colonia, Uruguay.
2The Australian Wine Research Institute, Waite Road, PO Box 197, Glen Osmond, SA 5064, South Australia, Australia. *Corresponding author (Daniel.Cozzolino@awri.com.au).