This study was performed with growing chicken (14 to 56 d of age) to evaluate the effects of feeding them a barley or triticale-based diet. The treatments were corn diet (1) as a control, hulless barley diet with (5) or without (2) enzyme, triticale diet with (6) or without (3) enzyme and hulled barley diet with (7) or without (4) a commercial beta-glucanase enzyme. In a digestibility trial, 21 male broiler chicks were used at 45 days old. Each of the seven treatments was replicated three times. No significant difference (P>0.05) was observed between (2) to (7) treatments with corn diet for weight gain and feed intake during growing period, but hulled barley with no treatment (4) had less weight gain and higher feed conversion (lower efficiency) than other cereals. Ether extract digestibility increased significantly in all the enzyme treated diets compared to corn diet (P<0.05). Metabolizable energy corrected for nitrogen (AMEn) was less in hulled barley with no treatment, compared to corn and triticale treated with enzyme (P<0.05). Reduction of serum cholesterol was observed in birds on hulless barley diet (P<0.05), but serum creatinin did no show any significant difference between treatments (P>0.05). Higher serum immunoglobulin (IgG) was detected in broiler fed the hulled barley diet with no treatment, than the enzyme-treated barley and corn diets (P<0.05). Mean percentage of liver showed the highest percentage in hulled barley diet with no treatment (P<0.05) and fresh carcass was the lowest in chickens on triticale with no treatment (P<0.05). It was concluded that the enzyme supplementation is beneficial in terms of weight gain, feed intake, and feed conversion during 14-42 days old in chickens, but these positive effects of enzyme will be fade in aged chicken due to the higher capacity of alimentary tract for digestion of feed materials.