饲料蛋白质和能量含量对云纹龙胆石斑鱼幼鱼生长、体组成及消化酶活力的影响

Effects of Dietary Protein and Energy Levels on Growth, Body Composition and Digestive Enzymes Activities of Juvenile Hybrid Grouper, Epinephelus lanceolatus♂×E. moara♀

为探求云纹龙胆石斑鱼(Epinephelus lanceolatus♂×E.moara♀)幼鱼饲料的最适蛋白质和能量含量,以鱼粉和大豆浓缩蛋白为蛋白源、添加鱼油构建能量梯度,配制粗蛋白含量为46%、50%和54%,能量含量为20.00、20.50和21.00 k J/g,蛋能比为22.04~26.87 mg/k J的9组饲料,编号为D1~D9组,投喂初始体重为(46.23±0.51)g的云纹龙胆石斑鱼幼鱼56 d。结果显示,蛋白质和能量的交互作用对云纹龙胆石斑鱼幼鱼增重率影响显著(P<0.05),蛋白质和能量升高显著提高增重率和特定生长率(P<0.05)。蛋白质和能量的交互作用对蛋白质沉积率和肝体比影响显著(P<0.05),蛋白质升高显著提高能量保留率和肥满度(P<0.05),蛋白质效率先升后降(P<0.05);能量升高显著提高蛋白质效率和能量保留率(P<0.05);D6组蛋白质沉积率和蛋白质效率显著高于其他组(P<0.05)。蛋白质和能量的交互作用对全鱼及肌肉水分、粗蛋白、粗灰分均无显著影响(P>0.05),全鱼及肌肉粗蛋白随饲料粗蛋白升高而升高(P<0.05),水分随能量升高而降低(P<0.05),全鱼粗脂肪随蛋能比降低而升高(P<0.05)。蛋白质和能量的交互作用对胰蛋白酶、脂肪酶和淀粉酶活力影响显著(P<0.05),胃蛋白酶活力随蛋白质含量升高而升高(P<0.05),能量对其无显著影响(P>0.05);D6组胰蛋白酶活力最高,其随饲料蛋能比降低呈先升后降的趋势(P<0.05),能量为21.00 k J/g时,脂肪酶活力显著高于其他组(P<0.05)。综上,在设定的蛋白质和能量范围内云纹龙胆石斑鱼幼鱼饲料以50%粗蛋白,21.00 k J/g能量为宜。

In order to investigate the optimal dietary protein and energy levels of a new juvenile hybrid grouper(Epinephelus lanceolatus♂×E.moara♀),nine diets were formulated containing three dietary protein levels(46%,50%and 54%crude protein)and three dietary energy levels(20.00 kJ/g,20.50 kJ/g and 21.00 kJ/g gross energy),the dietary protein-energy ratio was in the range of 22.04 to 26.87 mg/kJ.Juvenile grouper averaging(46.23±0.51)g were fed the test diets for 56 days.The results indicated that the interaction between protein and energy had a significant effect on the weight gain(WG)of grouper(P<0.05),the weight gain rate(WGR)and specific growth rate(SGR)increased with increasing of dietary protein and energy levels(P<0.05).Protein deposition rate(PDR)and hepatosomatic index(HSI)were significantly affected by the interaction between protein and energy(P<0.05).The energy retention rate(ERR)and condition factor(CF)increased with increasing of dietary protein levels(P<0.05),while the protein efficiency ratio(PER)increased first and decreased afterwards(P<0.05).The PER and ERR increased with increasing of dietary energy levels(P<0.05).PDR and PER of D6 group were significantly higher than other groups(P<0.05).The interaction of protein and energy had no significant effects on moisture,crude protein and crude ash of whole fish and muscle(P>0.05).The crude protein of whole fish and muscle increased with increasing of dietary protein levels(P>0.05).Moisture decreased with increasing of dietary energy levels(P<0.05).Crude fat of whole fish increased with decreasing of dietary protein-energy ratio(P<0.05).The interaction of protein and energy had significant effect on the activities of trypsin,lipase and amylase(P<0.05).The pepsin activity increased with increasing of dietary protein levels(P<0.05),and dietary energy levels had no significant effect on it(P>0.05).The trypsin activity of D6 group was significantly higher than other groups(P<0.05),which increased first and then decreased with decreasing of dietary protein-energy ratio(P<0.05).The lipase activity of fish fed diets containing 21.00 kJ/g energy was significantly higher than other groups(P<0.05).According to these results,a diet containing 50%protein and 21.00 kJ/g energy was recommended for efficient growth of juvenile hybrid grouper.