Gravimetric Determination of Acid Detergent Fiber and Lignin in Feed: Interlaboratory Study

Abstract On the basis of AOAC Official Method 973.18, a collaborative study was performed to determine fractions of acid detergent fiber (ADF) and lignin (ADL) in animal feed. The study used 6 animal feed and forage samples as blind duplicates and involved 22 participants from 7 countries. The samples analyzed covered a range from 3.5 to 70 ADF and from <1 to 20 ADL. Repeatability standard deviations ranged from 0.27 to 0.95 for ADF and from 0.08 to 0.59 for ADL. The reproducibility standard deviations ranged from 0.56 to 2.44 for ADF and from 0.52 to 2.09 for ADL. Analyzed samples comprised clover and grass silages, soy meal, cattle feed, wheat, and sawdust. The studied method has been published as the EN ISO 13906:2008 standard.