parametersThe CP, aNDF, ADF and ADL contents of OA were similarto those reported by Gasmi-Boubaker et al. (2007). How-ever, they reported that the condensed tannin (CT) in acornwas 45 g/kg DM which is higher than that of present study(e.g., 10 g/kg DM). This inconsistency could be due to thedifference between species of oaks and also the methodsused for measuring of tannins.The low values of DOM and DDM in animals receivingOA could be attributed to the presence of tannins (Al-Jassimet al., 1998). The reduction in nutrients digestibility wasmore prominent in DCP and DNDF. The presence of tanninsin the diet could be a main factor having adverse effects