A study was conducted during spring in the North-West of Tunisia to determine: the chemical composition; the in situ disappearance; and the in vitro fermentation of eight dominant woody species in the region of experimentation. Dry matter (DM), organic matter (OM) and crude protein (CP) degradation were measured by the nylon bag technique on three rumen-fistulated local goats. Animals were browsing freely daily and provided the rumen fluid used for the fermentation study in syringe. Oat hay served as a control. Shrubs had moderate levels of CP except C. villosa, which had the highest. The degree of lignification was important in all shrubs. In situ DM degradation and volume of gas produced after 120 h varied. The lowest DM disappearance and gas production was recorded with Q. suber, which had the highest ADL content. There were relationships between lignin content, in situ degradation and in vitro fermentation. Ranking of shrubs according to their DM and OM degradation was similar using in vitro gas production. Further work is needed to account for the anti-nutritional factors content.