Abstract: The purpose of this study was to assess the effects of compound enzymes with different zymograms on growth performance, serum biochemical indexes and number of intestinal flora of broilers. A total of 480 28-day-old white-feathered broilers were selected and randomly divided into 4 groups with 12 replicates in each group and 10 broilers （half males and half females） in each replicate. The broilers in control group were fed with a corn-soybean meal diet, and those in experimental groups Ⅰ, Ⅱ and Ⅲ fed the same basal diet as control group were supplemented with 200 g/t compound enzymes with different zymograms. The experimental period was 15 days (28 to 42 days of age of the broilers). The ratio of feed to gain, serum biochemical indexes and number of intestinal flora of broilers in different groups were determined and statistically compared. The results showed that compared with the control group, the ratio of feed to gain of experimental groups Ⅰ, Ⅱ and Ⅲ was extremely significantly decreased by 1.01% （P<0.01）, 2.20% （P<0.01） and 0.83% （P<0.01）, respectively; there was extremely significant （P<0.01） difference in ratio of feed to gain among experimental group Ⅱ and experimental groups Ⅰ and Ⅲ. Compared with the control group, the total protein and albumin contents of experimental groups Ⅰ, Ⅱ and Ⅲ were extremely significantly increased by 10.08%-11.41% （P<0.01） and 12.00%-12.93% （P<0.01）, respectively. Compared with the control group, the number of intestinal Escherichia coli in experimental groups Ⅰ, Ⅱ and Ⅲ was extremely significantly decreased by 17.87% （P<0.01）, 26.43% （P<0.01） and 21.67% （P<0.01）, respectively; extremely significant （P<0.01） difference in number of intestinal Escherichia coli between experimental group Ⅰ and experimental group Ⅱ was observed, and significant （P<0.05） difference was also found among experimental group Ⅲ and experimental groups Ⅰ and Ⅱ. Compared with the control group, the number of intestinal Lactobacillus in experimental groups Ⅰ, Ⅱ and Ⅲ was extremely significantly increased by 13.99% （P<0.01）, 26.10% （P<0.01） and 24.06% （P<0.01）, respectively; there was extremely significant （P<0.01） difference in number of intestinal Lactobacillus among experimental group Ⅰ and experimental groups Ⅱ and Ⅲ. In summary, the dietary supplementation of compound enzymes with different zymograms had certain improving effects on growth performance, serum biochemical indexes and number of intestinal flora of broilers. Furthermore, the compound enzymes with different zymograms have varied performance in improving the production performance associated indexes of broilers. The results obtained in this study provide references for collocation of high-efficient compound enzymes in practical production.

Key words: compound enzymes, production performance, biochemical indexes, number of flora, broilers