Instantaneous determination of crude proteins, fat and fibre in animal feeds using near infrared reflectance spectroscopy technology and a remote reflectance fibre-optic probe

In the present study we address the development of a rapid technique – near infrared reflectance spectroscopy (NIRS) technology and the use of a remote reflectance crude fibre (CF)-optic probe (fitted with a 5 cm × 5 cm quartz window) – to perform instantaneous analysis of quantitative parameters such as the ether extract (DM), crude protein (CP) and crude fibre in animal feed and fodder. The technique does not involve the destruction or treatment of the sample because it is based on direct application of a fibre-optic probe on the feed (with different physical characteristics, such as commercialisation in the form of meal, tablets and granules) given to cattle, swine, sheep, birds and rabbits that is used in different stages of animal development—juvenile development, growth, fattening, etc. The regression method employed was modified partial least squares (MPLS). The calibration results using 72 samples permitted the determination of crude protein, the ether extract and crude fibre. This calibration is applicable within the ranges for crude protein of 5–495 g kg−1; the ether extract, 16–66 g kg−1; crude fibre, 23–111 g kg−1, with multiple correlation coefficients (RSQ) for crude protein, the ether extract and crude fibre of 0.991, 0.932 and 0.848, respectively. The standard errors of prediction corrected (SEPC) for the above parameters in g kg−1 were 12.5, 2.09 and 6.05, respectively. The robustness of the analytical method was confirmed by applying it to 10 samples for external validation. sults obtained indicate that NIRS with a fibre-optic probe can be used as a quality control method in animal feeds and fodder for the determination of crude protein, the ether extract and crude fibre.