本试验旨在探讨饲料中不同添加比例木薯粉对罗非鱼营养物质表观消化率、肠道和肝胰脏消化酶活性以及血清非特异性免疫指标的影响。试验选择健康、平均体重为（7.50±0.25）g的罗非鱼540尾，随机分为6组（每组3个重复，每个重复30尾），分别饲喂木薯粉添加比例为0（对照）、4%、8%、12%、16%和20%的等能等氮试验饲料，试验期为8周。结果表明：与对照组相比，饲料中添加4%~20%木薯粉对罗非鱼粗脂肪和钙的表观消化率均无显著影响（P>0.05）；饲料中添加4%~16%木薯粉对罗非鱼干物质、粗蛋白质、粗灰分和总磷的表观消化率无显著影响（P>0.05）；饲料中添加4%~12%木薯粉对罗非鱼肠道和肝胰脏蛋白酶活性无显著影响（P>0.05）；饲料中木薯粉添加比例在20%以内均可提高（P>0.05）或显著提高（P<0.05）肠道和肝胰脏脂肪酶和淀粉酶的活性；饲料中木薯粉添加比例在4%~12%时可提高血清溶菌酶和超氧化物歧化酶的活性，但是差异不显著（P>0.05），对血清其他非特异性免疫指标也无显著影响（P>0.05）。根据结果综合评定，在本试验饲料营养水平的基础上，木薯粉在罗非鱼饲料中添加比例为4%~12%时不会对罗非鱼的营养物质表观消化率、肠道和肝胰脏消化酶活性及血清非特异性免疫指标产生不良影响，可节约饲料成本。

This study aimed to explore dietary different supplemental proportion of cassava meal on nutrient apparent digestibility, digestive enzyme activities in intestine and hepatopancreas, and serum non-specific immune indices of tilapia. A total of 540 healthy tilapia with the average body weight of (7.50±0.25) g were selected and randomly divided into 6 group with each group had three replicates and each replicate had 30 fish. The fish in the 6 groups were fed isoenergetic and isonitrogenous experimental diets with the cassava meal supplemental proportions were 0 (control), 4%, 8%, 12%, 16% and 20%, respectively. The trial period was 8 weeks. The results showed as follows:compared with the control group, diets added 4% to 20% cassava meal had no significant effect on apparent digestibility of ether extract and calcium of tilapia (P>0.05); diets added 4% to 16% cassava meal had no significant effect on apparent digestibility of dry matter, crude protein, ash and phosphorus of tilapia (P>0.05); diets added 4% to 12% cassava meal had no significant effect on protease activity in intestine and hepatopancreas of tilapia (P>0.05); less than 20% cassava meal added in diets could improve (P>0.05) or significantly improve (P<0.05) the activities of lipase and amylase in intestine and hepatopancreas of tilapia; when diets cassava meal supplemental proportions were 4% to 12%, serum lysozyme and superoxide dismutase activities were increased, but differences were not significant (P>0.05), and there were no significant effects on other serum non-specific immune indices (P>0.05). According to the results of comprehensive evaluation on the basis of dietary nutrient levels in this trial, diets added 4% to 12% cassava meal do not have bad effects on nutrient apparent digestibility, digestive enzyme activities in intestine and hepatopancreas, and serum non-specific immune indices of tilapia, and can reduce the feed cost.