Changes in digesta parameters were examined in turkeys fed for 8 weeks on diets with and without the addition of an enzymatic preparation, Kemzyme®W Liquid, in doses of 50, 100 and 150 mg/kg. The preparation contained a specified mixture of xylanase and glucanases. The diet with the highest addition of exogenous enzymes decreased ileal viscosity (1.21 vs 1.33 mPa∙s) and weight of ileal tissue (10.6 vs 13.4 g/kg BW) compared with the control group. Dietary enzymes did not influence either hydration or pH of caecal digesta, but decreased the activity of bacterial enzymes as well and tended to increase short-chain fatty acid contents in the caeca. The highest dietary addition of an enzymatic preparation decreased caecal viscosity (3.04 mPa∙s) compared with the control (3.79 mPa∙s) and other experimental groups (3.50-3.51 mPa∙s).