Effects of dietary protein levels on the activities of digestive enzymes and the muscle compositon of juvenile red swamp crayfish Procambarus clarkii Girard | 饲料蛋白质水平对克氏原螯虾幼体消化酶活性和肌肉成分的影响

Chinese. 用4种等能不同质量分数的蛋白质饲料（30％、35％、40％和45％）饲喂克氏原螯虾（Procambarus clarkii Girard）幼虾（5．46g±0．51g）28d后，分析不同蛋白水平的饲料对克氏原螯虾幼虾肠道和肝胰脏消化酶活性和体成分的影响。结果表明：（1）饲料蛋白质浓度对脂肪酶和蛋白酶活性均有显著性影响（P〈0．05）；并随着饲料蛋白水平的提高，两酶活性都呈现先升高后降低的趋势。其中肠道蛋白酶和肝胰脏蛋白酶活性分别在饲料蛋白质浓度为40％和35％时最高；肠道和肝胰脏脂肪酶活性均在饲料蛋白质浓度为40％时最高，且各饲料组肝胰脏脂肪酶活性差异显著（P〈0．05），而35％组和40％组之间的肠道脂肪酶活性无显著性差异（P〉0．05）。克氏原螯虾幼体的肠道和肝胰脏淀粉酶活性随饲料蛋白质水平的升高均呈波浪式变化；35％组与45％组之间的肠道淀粉酶活性和30％与45％组之间的肝胰脏淀粉酶活性均无显著性差异（P〉0．05）。（2）随着饲料中蛋白水平的升高，克氏原螯虾肌肉中蛋白质含量只有45％组显著升高（P〈0．05），其他饲料组肌肉蛋白含量虽有上升趋势，但差异不显著（P〉0．05）。随着饲料蛋白浓度的增加，肌肉中脂肪含量反而下降，除30％组外，各组间差异显著（P〈0．05）。对克氏原螯虾肌肉灰分的测定表明，饲料蛋白浓度对肌肉中灰分含量的影响不显著（P〉0．05）。[著者文摘]

English. The juvenile of red swamp crayfish （5.46 g±0.51 g.） were fed for 28 days with four protein concentration diets（30% ,35% ,40% ,45% ） ,which were equal in energy, then the effects of dietary protein levels on the activities of digestive enzymes and muscle composition of juvenile red swamp crayfish were analyzed. The results showed that the lipase and protease activities in the intestine and hepatopancreas were significantly influenced by dietary protein level （P 〈 0.05 ） ; With the increase of the dietary protein level, the lipase and protease activities in the intestine and hepatopancreas increased firstly and then dropped. The protease activities in the intestine and hepatopancreas were the highest when the dietary protein level were 40% and 35% respectively; The lipase activities in the intestine and hepatopancreas were both the highest when the dietary protein level was 40%, but there was no significant difference between 35% and 40% （P 〉 0. 05 ）. The amylase activity changes in the intestine and hepatopancreas of the juvenlie red swap crayfish both were of wave types with the dietary protein level increasing：The amylase activity in the intestine was significant difference among every treatment except 35% and 45% groups （P 〈 0.05 ） ; The amylase activity in hepatopancreas was significant difference among every treatment except 30% and 45% groups （P 〈 0.05）. The protein contents in tousle of juvenile red swamp crayfish was higher with the dietary protein level increasing, but there was no significant difference among every treatment except the groups of 30% and 45% （P 〉 0. 05 ） ; The fat contents in muscle of red swamp crayfish was dropped with the dietary protein level increasing, and there were significant difference among every treatment （P 〈 0.05 ）. The result showed that there no significant difference between the ash content in the muscle and the dietary protein level.