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采用单因素随机区组设计,选择平均初重34.5±5.5g的大菱鲆幼鱼225尾,平均分为5组(A~E),每组3重复。分别饲喂蛋白质水平45%,48%,50%,52%和54%的5种膨化颗粒饲料,研究大菱鲆幼鱼的蛋白质消化特征及其对水环境的影响。结果表明:随着饲料蛋白质水平的提高,幼鱼的生长性能提高,饲料系数相应降低;蛋白质消化率先升后降,在50%蛋白组取得最大;蛋白质摄入量、消化量以及粪氮排出量明显增加;养殖水环境中氨氮和亚硝氮的浓度也不断提高。特别是在50%蛋白质水平以上时,幼鱼生长性能提高幅度缓慢,而粪氮排出量和水环境中氨氮含量显著提高(p<0.05)。试验表明,大菱鲆幼鱼环保饲料中蛋白质的适宜水平为50%。
One-factor randomized block design was used to select 225 turbot juveniles with an average initial weight of 34.5 ± 5.5g, divided into 5 groups (A to E), with 3 replicates in each group. Five kinds of puffed pellets with protein levels of 45%, 48%, 50%, 52% and 54% were respectively fed to study the protein digestion characteristics of juvenile turbot and their effects on water environment. The results showed that with the increase of dietary protein level, the growth performance of juvenile fish increased and the feed coefficient decreased accordingly. The digestibility of protein increased first and then decreased and reached the maximum in 50% protein group. The protein intake, digestion, Significantly increased; aquaculture water environment, ammonia nitrogen and nitrite nitrogen concentrations are also rising. Especially at 50% protein level, the growth performance of juvenile fish increased slowly, but the amount of excreted nitrogen and ammonia nitrogen in water environment increased significantly (p <0.05). Tests showed that the optimum level of protein for green juvenile turf feed was 50%.