摘要This experiment was conducted to determine whether the performance of broilers fed diets based on corn and soybean meal could be enhanced with enzymes or probiotics.A total of 120 male broilers,three days of age,were assigned to one of four treatments in a completely randomized design,and housed in groups of five with six cages per treatment.The control diet was based on corn and soybean meal while the three experimental diets consisted of the basal diet supplemented with 0.1% of enzyme Ⅰ,enzyme Ⅱ,or probiotic.Enzyme Ⅰ provided α-galactosi-dase and β-mannanase,while enzyme Ⅱ provided protease,amylase,α-galactosidase,xylanase,and cellu-lase.The probiotic was composed of Bacillus coagu-lance,Bacillus lichenformis,Bacillus subtilis,and Clostridium butyricum.Over the 28 day experiment,the weight gain of birds fed the probiotic treatment was superior (P = 0.03) to the control,while gains for the enzyme treatments were intermediate to those of the control and probiotic.Feed intake and feed conversion did not differ among treatments (P > 0.05).Ammonia production was significantly ( P < 0.01) higher in the control compared with either of the enzyme or probiotic treatments.Compared with the control,supplementation with enzyme Ⅱ significantly reduced the digestibility of arginine,isoleucine,and lysine (P <0.05).In contrast,the digestibility of energy was higher ( P < 0.01) for birds supplemented with enzyme Ⅱ than the control.Digestibility coefficients did not differ for any other parameter with the exception of energy which was significantly higher for birds fed the probiotic treatment than the control (P < 0.01).In summary,the performance of broilers was significantly enhanced by the addition of a probiotic to the diet.However,under the conditions of this experiment,supplementation with a multi-enzyme complex containing either α-galactosidase and β-mannanase or the combination of protease,amylase,galactosidase,xylanase,and cellulase failed to improve broiler performance.