饲料蛋白水平对方格星虫稚虫日增重和消化酶活性的影响

为探讨饲料蛋白水平对方格星虫稚虫日增重和消化酶活性的影响,以9种蛋白水平(25.21%、29.87%、35.03%、40.67%、45.47%、50.12%、55.29%、60.38%、64.85%)的等能微颗粒饲料(以D1-D9表示)饲喂稚星虫8周。结果表明,饲料蛋白水平对稚星虫的日增重有显著影响(P<0.05)。随着饲料蛋白水平的提高,稚星虫的日增重呈先增后降的趋势,在D5组达到最大值。对稚星虫消化酶活性的分析表明,稚星虫蛋白酶活性随着饲料蛋白水平的上升呈先增后降的趋势,在D6组达到最大值,且显著高于D1-D5组(P<0.05);淀粉酶和脂肪酶活性随着饲料蛋白水平的上升有显著降低的趋势(P<0.05),D9组稚星虫的淀粉酶活性显著低于D1-D4组(P<0.05);D9组稚星虫脂肪酶活性显著低于除D8组外的其他各蛋白水平组(P<0.05)。以日增重为评价指标,稚星虫对饲料蛋白的适宜需求量为46.69%。

Effects of dietary protein levels on weight growth and digestive enzyme activities of peanut worm, Sipunculus nudus Linnaeus, larvae

Effects of dietary protein levels on weight growth and digestive enzyme activities of peanut worm,Sipunculus nudus,Larvae were investigated by feeding 9 isocaloric diets(D1-D9) with 9 protein levels(25.21%,29.87%,35.03%,40.67%,45.47%,50.12%,55.29%,60.38%,64.85%) for 8 weeks.The results showed that protein levels significantly affected weight growth of S.nudus larvae(P<0.05).With the increased of dietary protein levels,the weight growth(WG) was firstly increased and then decreased,and the WG of D5 produced the maximum value.The results of digestive enzyme analysis showed that dietary protein levels had significant effects on digestive enzyme activities(P<0.05).With the increasing doses of dietary protein levels,the protease activity was firstly increased and then decreased,and protease activity of D6 produced the maximum value,and was significantly higher than D1 to D5(P<0.05).Both amylase activity and lipase activity significantly decreased with the increasing doses of dietary protein levels(P<0.05),and activities of amylase and lipase produced the minimum value in the D9 group.From basis on comprehensive analysis on WG,it was concluded that the suitable dietary protein level for S.nudus larvae should be 46.69%.