Use of near infrared reflectance spectroscopy (NIRS) to analyse animal feeds

Abstract

Near infrared reflectance spectroscopy (NIRS) was used to predict both chemical composition of animal feed samples and the contamination of meals of vegetal origin with meals of animal origin. Four hundred (n:400) animal feed samples of wide range on chemical characteristics and origin were scanned in an instrument NIRS 6500 (NIRSystems, Silver Spring, MD, USA) over the wavelength range between 400 - 2500 nm, in reflectance mode. Calibration coefficients of determination (R²) and standard error in cross validation (SECV) were 0.90 (SECV: 0.82%), 0.98 (SECV: 1.3%), 0.93 (SECV: 1.4%), 0.80% (SECV: 5.3%) and 0.92 (SECV:1.03%) for dry matter (DM), crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF) and ash, respectively, dry weight basis. The results showed that NIRS could be used as routine method to determine CP, ADF and ash in animal feed samples. In relation with the second objetive, good predictions were obtained for determine contamination in soy bean meal with either fish meal or meat and bone meal.