This experiment was conducted to investigate the effects of low energy diets supplemented with different doses of complex enzyme on growth performance,nutrient utilization and organ indexes of broilers.Three hundred and twenty one-day-old broilers were randomly assigned to four groups with eight replicates per group and ten broilers per replicate.The positive control (PC) group was fed a conventional diet (corn-soybean meal type diet).Relative to the diet of PC group,the metabolizable energy (ME) of the negative control (NC) group diet was reduced by 210 kJ/kg,and the contents of miscellaneous meal and wheat ingredients were increased.The conventional additive dose of enzyme (CADE) and high additive dose of enzyme groups were fed the NC group diet supplemented with 0.02％ and 0.20％ complex enzyme,respectively.The trial lasted for 21 d.The results showed as follows:the average daily gain in the HADE group was significantly higher than that in the other groups (P ＜ 0.05),but there was no significant difference among the other groups (P ＞ 0.05).The feed/gain in the PC,CADE and HADE groups was significantly lower than that in the NC group (P ＜0.05 or P ＜0.01),and the feed/gain in the HADE group was significantly lower than that in the CADE and PC groups (P ＜ 0.05),while no significant difference was found between CADE and PC groups (P ＞ 0.05).As for dry matter apparent metabolizability,the HADE group was significantly higher than the NC group (P ＜ 0.05),but there was no significant difference among the other groups (P ＞ 0.05) ; as for crude protein apparent metabolizability,the CADE and HADE groups were extremely significantly and significantly higher than the PC (P ＜ 0.01) and NC groups (P ＜ 0.05),respectively ; as for ether extract apparent metabolizability,the NC group was extremely significantly lower than the other groups (P ＜ 0.01),and the CADE and PC groups were significantly lower than the HADE group (P ＜ 0.05) ; as for apparent metabolizable energy,the HADE group was significantly higher than the other groups (P ＜ 0.05),but there was no significant difference among the other groups (P ＞ 0.05) ; as for energy apparent metabolizability,the CADE and HADE groups were extremely significantly higher than the PC and NC groups (P ＜ 0.01),and the HADE group was significantly higher than the CADE group (P ＜ 0.05).Compared with the NC group,the indexes of stomach,pancreas and liver in CADE and HADE groups were significantly or extremely significantly decreased (P ＜ 0.05 or P ＜ 0.01),while the bursa of Fabricius index was significantly or extremely significantly increased (P ＜ 0.05 or P ＜ 0.01).In conclusion,the supplementation of complex enzyme in the diet,in which the ME is reduced by 210 kJ/kg and the contents of miscellaneous meal and wheat ingredients are increased,the growth performance,nutrient utilization and organ indexes of broilers are improved.The effect of complex enzyme is significantly increased when the dose of complex enzyme is enhanced from 0.02％ to 0.20％.%本试验旨在研究在降低能量的饲粮中添加不同剂量复合酶对肉鸡生长性能、养分利用率和器官指数的影响.将320只1日龄爱拔益加肉鸡随机分为4组,每组8个重复,每个重复10只.正对照组饲喂常规饲粮(玉米-豆粕型饲粮)；负对照组饲喂低能饲粮,饲粮配方相对于正对照组增加了杂粕和麦类原料的用量,同时使代谢能降低210kJ/kg;常规剂量加酶组和高剂量加酶组分别饲喂在负对照组饲粮基础上添加0.02％和0.20％复合酶的饲粮.试验期为21 d.结果表明:高剂量加酶组的平均日增重显著高于其他各组(P＜0.05),其他各组之间无显著差异(P＞0.05).高剂量加酶组的料重比极显著低于负对照组(P＜0.01),常规剂量加酶组和正对照组料重比均显著低于负对照组(P＜0.05),常规剂量加酶组和正对照组之间无显著差异(P＞0.05).干物质表观代谢率,高剂量加酶组显著高于负对照组(P＜0.05),其他组间无显著差异(P＞0.05)；粗蛋白质表观代谢率,高剂量加酶组极显著高于正对照组和负对照组(P＜0.01),常规剂量加酶组显著高于正对照组和负对照组(P＜0.05)；粗脂肪表观代谢率,负对照组极显著低于其他各组(P＜0.01),正对照组和常规剂量加酶组显著低于高剂量加酶组(P＜0.05)；表观代谢能,高剂量加酶组显著高于其他各组(P＜0.05),其他组间无显著差异(P＞0.05)；能量表观代谢率,常规剂量加酶组和高剂量加酶组均极显著高于正对照组和负对照组(P＜0.01),高剂量加酶组显著高于常规剂量加酶组(P＜0.05).与负对照组相比,常规剂量加酶组和高剂量加酶组的胃、胰腺和肝脏指数显著或极显著降低(P＜0.05或P＜0.01),法氏囊指数显著或极显著升高(P ＜0.05或P＜0.01).由此得出,在增加杂粕和麦类原料的用量并使代谢能降低210 kJ/kg的饲粮中添加复合酶对肉鸡生长性能、养分利用率和器官指数具有很好的改善作用；相对于0.02％的添加量,0.20％添加量可进一步提高复合酶的应用效果.
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