Evaluation of Forages in the Laboratory. IV. Within and among Trial Variability of the Wisconsin Artificial Rumen Procedure

Within and among trial variability of an artificial rumen procedure used for forage evaluation were estimated. Comparison of forages ground through a 40or 60-mesh screen revealed that finer grinding increased in vitro digestibility of grasses and legumes but the digestibility of graases was increased to a greater extent. No significant difference was found in the correlation of in vitro cellulose digestion and in vivo DDI~[ due to fineness of grind. It was suggested that grinding be standardized within a laboratory.