New Advances in Analyzing Soybean Composition
Near-infrared reflectance spectrometers (NIRS) have been used by the feed industry for about 25 years. This technology provides for rapid analysis of compositional compounds of dry matter, crude protein, fat crude fiber, acid detergent fiber, starch, sugar and more recently amino and fatty acids. Degussa Corporation researchers reported after five years of industry testing that calibrations are now available that can determine composition values of various feed ingredients with the speed and accuracy needed by the feed industry. Of particular interest is the calibration for amino acids. In the fifth ring test, involved 52 laboratories, seven feed ingredients that were provided in ground and unground forms. They found that the coefficient of variation (variation divided by the mean) for ground samples was less than the unground samples, but the differences were not large. More important was the conclusion that the analytical differences in dry matter, crude protein and amino acids were similar between the various laboratories and the central laboratory and the relative differences between laboratories for these components were well below four percent. Of interest were the reported coefficient of variations for components of soybean meal; with 44 instruments, the CV for dry matter, crude protein, methionine, methionine plus cysteine, lysine, threonine and tryptophan were: 0.25, 0.69, 1.23, 1.18, 0.82, 0.84 and 1.12 percent, respectively.
Goodson, J., J. Fontaine and B. Schirmer. 2005. NIRS can help predict amino acid content. Feedstuffs, September 19. p20-22, 24.