饲料中不同蛋白质水平对半刺厚唇鱼幼鱼生长性能及消化酶活性的影响

Effect of Feed Protein Levels on Growth Performance and Digestive Enzyme Activity of Juvenile Acrossocheilius hemispinus

为确定半刺厚唇鱼幼鱼的蛋白质需要量,以鱼粉和豆粕为蛋白源,添加鱼油、豆油、α-淀粉、纤维素以及适量的维生素和矿物质配制成试验饲料。蛋白质质量分数设置26%、30%、34%、38%、42%、46%等6个水平,饲养平均体重(12.51±0.15)g的半刺厚唇鱼幼鱼56天后,以增重率、饲料系数和肠道消化酶活性为评价指标,分析不同蛋白水平的饲料对半刺厚唇鱼幼鱼生长和体内消化酶活性的影响。结果表明:在6个试验组中,增重率最大的为42P组,其次为38P组,两组之间显著不差异(P>0.05),增重率最小的26P组;饲料系数随蛋白质水平递增呈现出先逐渐减小后升高的趋势,其中42P组的饲料系数最小,其次为38P组,但两者差异不显著(P>0.05)。试验鱼肠道胰蛋白酶活性表现出随着饲料中蛋白质水平的增加而先升后降的趋势,其中38P组的胰蛋白酶活性最高且显著高于其他试验组(P<0.05)。综上所述,考虑到饲料成本和对养殖水环境的氮磷排放率等因素,半刺厚唇鱼幼鱼配合饲料中适宜的蛋白质水平为38%。

To determine the protein requirement amount of juvenile Acrossocheilius hemispinus, fishmeal andsoybean meal were used as protein source, fish oil, soybean oil, α-starch, cellulose and appropriate amount ofvitamins and minerals were added into test feed. Juvenile A. Hemispinus [average weight（12.51±0.15） g] wereraised for 56 days with feed protein level of 26%, 30%, 34%, 38%, 42% and 46%, the effects of differentprotein levels on the growth and digestive enzyme activities of juvenile A. hemispinus were analyzed bycomparing weight gain, feed coefficient and intestinal digestive enzyme activities. The results showed that themaximal weight gain rate was observed in 42 P group, and then was in 38 P group, the difference between thetwo was not significant（P〈0.05）, the minimal weight gain rate was observed in 26 P group. The feed coefficientfirst decreased then rose with the increase of protein level, the lowest group was 42 P and then was 38 P, but thedifference was not significant（P〈0.05）. The activities of trypsin in the intestine showed a trend of first risingand then decreasing with the increase of protein level in the feed, the highest group was 38 P and the difference was significant（P〈0.05） from other groups. To sum up, the appropriate feed protein level for juvenile A.hemispinus is 38%.