NEAR-INFRARED REFLECTANCE SPECTROSCOPY TO PREDICT ENERGY VALUE OF COMPOUND FEEDS FOR SWINE AND RUMINANTS

Near infrared reflectance spectroscopy (NIRS) was compared with analyt ical methods for predicting chemical composition, digestibility and en ergy content of compound feeds for swine and ruminants. The study inve stigated numerous widely diversified feeds with known in vivo measurem ents (87 swine and 80 ruminant feeds). Accuracy of prediction of the e nergy values of swine and ruminant feeds using NIRS was slightly bette r than using empirical models from chemical composition or enzymatic m ethods. The two populations had to be modelled individually. Despite t he need of a large number of samples for calibration, NIRS measurement s are non-destructive, non-polluting and can be carried out during a s hort period of time. The most significant wavelengths selected by the step-up model for in vivo digestibility of swine and ruminant feeds la y in the range 1600-1700 nm and 2200 nm, respectively.