Near-infrared reflectance spectroscopy in precision feed formulation

Because of problems inherent in determining the digestible amino acid content of batches of feedstuffs used for the formulation of feeds, feed manufactures routinely overformulate for digestible amino acids. A producer wishing to assure that no more than 20% of the batches of feed produced are nutritionally inadequate must overformulate by 7.5% for a feed containing 65% maize, 25% soybean meal, and 5% poultry by-products when using randomly-selected batches of these feedstuffs. Selecting batches based on protein content allows for a reduction of this safety margin to 6.3%, since protein is a predictor, albeit a poor one, for digestible amino acid content. Near-Infrared Reflectance Spectroscopy (NIRS) was evaluated as a tool to directly predict the digestible amino acid content of animal meals with the objective to develop a nutritionally relevant quality control tool. Using a database containing 78 animal meals, we developed calibrations that explain 70-90% of the variation in digestible amino acid content. Achieving such a degree of accuracy for all feedstuffs of interest would permit overformulation to be reduced to 3%. The precision of NIRS technology and its short sample analysis time would give feed mills an efficient, economical quality control tool for producing feeds that more accurately match the nutritional profile calculated.