The constancy of the digested cell wall in grass

Abstract

SUMMARYThe quantity of in vitro digested cell wall was determined in the separated leaf and stem of Digitaria decumbens (pangola grass) fertilized at three different levels of nitrogen and cut after two different periods of regrowth. The treatment means ranged from 39·6 to 41·5 g digested cell wall per 100 g forage organic matter in leaf, and from 37·5 to 41·6 g in stem. For both leaf and stem the lowest mean amounts of digested cell wall were associated with the highest levels of fertilizer and the longer periods of regrowth. The results for nitrogen fertilizer were consistent with those from previous in vivo digestibility experiments, but when the effect of the total cell wall on digested cell wall was taken into account there were inconsistencies. The previous in vivo digestibility data were used in conjunction with the present results in support of a view that interpretation of digestibility data for grasses is best made by reference to a constant digested cell wall of 39·5 g/100 g forage organic matter.