Neutral detergent fiber (NDF) is the most common measure of fiber used for animal feed analysis, but it does not represent a unique class of chemical compounds.
NDF measures most of the structural components in plant cells (i.e. lignin, hemicellulose and cellulose), but not pectin.
[3] The process of determining NDF content involves a neutral detergent that dissolves plant pectins, proteins, sugars and lipids.
This leaves behind the fibrous parts such as cellulose, lignin and hemicellulose.
Recent nutritional requirement tables for ruminants report limits for NDF intake.