Near infrared reflectance spectroscopy to predict energy value of compound feeds for swine and ruminants

Near infrared reflectance spectroscopy (NIRS) was compared with analytical methods for predicting chemical composition, digestibility and energy content of compound feeds for swine and ruminants. The study investigated numerous widely diversified feeds with known in vivo measurements (87 swine and 80 ruminant feeds). Accuracy of prediction of the energy values of swine and ruminant feeds using NIRS was slightly better than using empirical models from chemical composition or enzymatic methods. The two populations had to be modelled individually. Despite the need of a large number of samples for calibration, NIRS measurements are non-destructive, non-polluting and can be carried out during a short period of time. The most significant wavelengths selected by the step-up model for in vivo digestibility of swine and ruminant feeds lay in the range 1600-1700 nm and 2200 nm, respectively.