本试验旨在通过研究饲料能量蛋白质比（E/P）对克氏原螯虾生长指标、肌肉组成、消化酶活性以及能量收支的影响，确定克氏原螯虾饲料最适E/P。配制5种不同E/P的相同粗蛋白质（CP）水平的半精制试验饲料，饲料CP水平为35%，E/P分别为32、34、36、38和40 MJ/kg，饲养平均体重（8.41±1.12）g的克氏原螯虾60 d。结果显示：成活率、相对增重率和相对增长率均随着E/P的升高呈现先升高后降低的趋势，均在E/P 36 MJ/kg组呈现最高水平，且在E/P 36 MJ/kg组饲料系数最低。不同饲料E/P对克氏原螯虾肌肉的水分、CP和粗灰分含量无显著性影响（P>0.05）；随着E/P上升，肌肉的粗脂肪含量出现逐渐上升的趋势。E/P 36 MJ/kg组的蛋氨酸（Met）和精氨酸（Arg）含量显著高于E/P 32和40 MJ/kg组（P<0.05）。随着E/P升高，克氏原螯虾体内肝胰腺的纤维素酶、淀粉酶、蛋白酶活性与肠道的纤维素酶活性均呈现先上升后下降的趋势，分别在E/P 36、36、36和34 MJ/kg组达到最高水平；肠道的淀粉酶活性呈现先下降后上升的趋势，分别在E/P 36和40 MJ/kg组呈现最低值和最高值（P<0.05）；各组克氏原螯虾肠道蛋白酶活性没有显著性差异（P>0.05）。随着饲料E/P上升，克氏原螯虾的摄入能呈现先上升后下降的趋势，E/P 36和38 MJ/kg组摄入能分别为52.63和51.19 KJ，显著高于其他组（P<0.05）；生长能/摄入能、排泄能/摄入能和粪能/摄入能呈现先上升后下降的趋势，而呼吸能/摄入能和蜕皮能/摄入能则呈现先下降后上升的趋势。综合以上各指标，克氏原螯虾饲料适宜E/P为34~36 MJ/kg。

This experiment was conducted to study the effects of different energy-protein ratios (E/P) on growth performance, muscle composition, the activities of digestive enzymes and energy budget of Procambrus clarkii. Five kinds of semirefined experimental diets with different E/P yet the same crude protein (CP) content were compounded. The CP content in the diets was 35%, and the E/P were 32, 34, 36, 38 and 40 MJ/kg, respectively. The Procambrus clarkiis with an average body weight about (8.41±1.12) g were fed 60 days. The results showed that the survival rate, relative weight gain rate and relative growth rate all had the pattern of first increase and then decrease while the E/P increased, with the peaks showed at 36 MJ/kg, significantly higher than those in the other groups (P<0.05). However feed conversion ratio at 36 MJ/kg was significantly lower than that in the other groups. Different E/P did not have any significant effects on the contents of moisture, crude protein and ash (P>0.05). With E/P increasing, the crude lipid content slowly increased in the muscle. The Met and Arg contents in the E/P 36 MJ/kg group were significantly higher than those in the E/P 32 and 40 MJ/kg groups (P<0.05). With E/P increasing, the activities of cellulose, amylase and protease in the hepatopancreas and cellulose in intestinal tract took the pattern of first increase and then decrease, with the highest levels in E/P 36, 36, 36 and 34 MJ/kg groups, respectively. The amylase activity in the intestinal tract took the pattern of first decrease and then increase, the peak and valley values in E/P 36 and 40 MJ/kg groups, respectively (P<0.05). The activity of protease in the intestinal tract of different groups did not show any significant difference (P>0.05). With E/P increasing, the ingestion energy had the pattern of a decrease after an increase, the peaks, 52.63 and 51.19 KJ, in E/P 36 and 38 MJ/kg groups, were significantly higher than those in the other groups (P<0.05); the growth/ingestion energy, urinary/ingestion energy and feces/ingestion energy had the pattern of a decrease after an increase, while respiratory/ingestion energy and exuviae/ingestion energy were contrary. In conclusion, the optimum E/P in the diet for the Procambrus clarkii is a range of 34 to 36 MJ/kg.