Prediction Of The Fermentative Quality Of Sunflower Silage By Nearinfrared Reflectance Spectroscopy (Nirs) On Oven-Dried Samples

The objective of the present work was to evaluate the predictive ability of calibration equations developed by NIRS (near-infrared reflectance spectroscopy) on dry and ground samples for estimating the fermentative quality of sunflower silage. NIRS spectra of a total of 52 oven-dried and ground silage samples from different laboratory silo tests carried out at the Mabegondo Agricultural Research Center (Centro de Investigacions Agrarias de Mabegondo, CIAM) were registered. The fresh samples were analyzed using reference methods. The pH, lactic acid, acetic acid, ethanol, ammonia nitrogen and soluble nitrogen levels were determined. NIRS calibrations were developed by modified partial least squares regression, performing a regression between spectral and reference data. The predictive capacity of the equations obtained ranged from excellent to good, with cross-validation coefficients of determination (r(cv)(2)) equal to or above 0.88. The RPD index values for all the parameters studied were equal to or above 3.0; therefore, the calibration equations obtained on dry and ground samples can be used satisfactorily to predict the fermentative quality of sunflower silages in routine analyses.