In our experiments we tested 11 kinds of different lignocellulose materials by means of the method in vitro according to Mellenberger et al. (1970) for a determination of their digestiblity. In experiments carried out with beech sawdust treated with 0.1 M of sulphuric acid a digestibility of 3.7% was found, in sawdust treated with 0.47 M of nitric acid a digestibility of 61.6% was found and after a neutralization with ammonia it amounted to 72.2%. Wood fibre (WF-1) treated enzymatically showed a digestibility of 28.6% and in the WF-2 complemented with newsprint paper it amounted to 33.4%. Untreated beech waste -- forest billets -- showed a low digestibility (5.6%) and that of zero fibre was somewhat higher (12.6%). Difibered beech sawdust showed a digestibility of 44.0% and the digestibility of the biomass prepared from lye waste obtained during the production of cellulose fibres amounted to 74.1%. Waste fibre also showed a high digestibility of 76.0%. Straw enriched with yeast proteins (SL-1) showed a digestibility of 58.0%. Cellulose used as a standard in the course of the testing of lignocellulose materials showed the highest digestibility -- 82.3%.