Assessment of Total Digestible Nutrients (TDN) of Hays from Its Chemical Composition

Abstract

Various raboratory methods for predicting TDN contents were tested and compared on 19 samples of grass or mixed hay and 7 alfalfa hay. For all samples TDN contents in vivo were determined with sheep or goat fed at a maintenance level. The methods investigated were Weende component (crude fiber), cell wall components (detergent analysis and enzymatic analysis), summative equation (enzymatic analysis) and Adams method. Considerably better results were obtained with method using various fractions determined by enzymatic analysis.