COMPARISON OF LABORATORY METHODS FOR PREDICTING DIGESTIBILITY OF FEEDSTUFFS

results in the prediction of the in vivo digestibility were obtained with the TILLEY & TERRY (1963) method, modified by ALEXANDER & MCGOWAN (1966) and by the in situ method, 48 hours of incubation + pepsin. There was a lower correlation between the results of the enzymatic methods and the in vivo digestibility, using Aspergillus niger and Trichoderma viride as sources of cellulase, though significant at a 5 % level, for the prediction of the in vivo dry matter digestibility and D value. The in situ dry matter degradability can be used to predict the in vivo dry matter digestibility, at almost all the incubation times, at a 5 % level of significance. The best results were obtained after 48 and 72 hours of incubation, r = 0.83 and r = 0.86, respectively. The results would indicate a good potentiality to predicting the dry matter digestibility from the rumen degradation characteristics of the forages