The use of the cellulase digestion procedure for indexing the dry matter digestibility of forages

Abstract

The in vitro cellulase technique was compared with the rumen liquor technique and found to be more efficient for the indexing of the dry matter disappearance (DMD) of forages. A cellulase enzyme concentration of 80 IU/gDM gave a satisfactory linear regression y = l,3585x + 11,6250 (R² = 0,6453; P ≤ 0,01) for the estimation of in vitro digestibility (y) from cellulase dry matter disappearance (CDMD) (x).

Using the modified laboratory procedure developed, two operators can analyse over 100 samples, in duplicate, each week. Over a period of 18 months the technique was used to index the digestibility of forages from a wide variety of rangeland sites in Natal.