饲料糖脂比对拟穴青蟹仔蟹生长性能、体组成和消化酶活性的影响

本试验旨在研究饲料糖脂比对拟穴青蟹仔蟹生长性能、体组成和消化酶活性的影响。以初始体重为(41.4±0.3)mg的拟穴青蟹仔蟹为试验对象,分别投喂糖脂比为0.54、0.88、1.39、2.08和3.50的等氮(约44%)等能(约19.5 MJ/kg)饲料3周。结果表明:1)饲料糖脂比对拟穴青蟹仔蟹的终末平均体重(FABW)、成活率(SR)、增重率(WGR)以及特定生长率(SGR)均有显著影响(P0.05)。随着饲料糖脂比的增大,拟穴青蟹仔蟹的FABW、SR、WGR以及SGR均呈先升高后降低的趋势,且均是糖脂比1.39试验组最高,显著高于糖脂比0.54和3.50试验组(P0.05)。2)饲料糖脂比对拟穴青蟹仔蟹的水分、粗蛋白质和粗灰分含量没有显著影响(P0.05),而对粗脂肪含量的影响显著(P0.05),糖脂比0.54试验组的脂肪含量最高,显著高于糖脂比2.08和3.50试验组(P0.05)。3)饲料糖脂比对拟穴青蟹仔蟹的淀粉酶活性没有显著影响(P0.05),但显著影响蛋白酶和脂肪酶活性(P0.05)。随着饲料糖脂比的增大,蛋白酶活性呈先增大后减小的趋势,脂肪酶活性呈降低的趋势,糖脂比1.39试验组的蛋白酶活性显著高于其他试验组(P0.05),糖脂比0.54和0.88试验组的脂肪酶活性显著高于糖脂比2.08和3.50试验组(P0.05)。以增长率为评价指标,经回归分析得出拟穴青蟹仔蟹饲料的适宜糖脂比为2.07。

Effects of Dietary Carbohydrate to Lipid Ratio on Growth Performance,Body Composition and Digestive Enzyme Activities of Juvenile Scylla paramamosain

A 3-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid (CHO ∶L) ratio on growth performance,body composition and digestive enzyme activities of juvenile Scylla paramamosain.Five iso-nitrogenous (about 44％) and iso-energetic (about 19.5 MJ/kg) diets with varying CHO ∶L ratios of 0.54,0.88,1.39,2.08 and 3.50 were fed to juvenile Scylla paramamosain with an average body weight of (41.4±0.3) mg of triplicate groups.The results showed as follows:1) dietary CHO ∶L ratio significant affected the final average body weight,survival rate,weight gain rate and specific growth rate of juvenile Scylla paramamosain (P＜0.05),and the final average body weight,survival rate,weight gain rate and specific growth rate of juvenile crabs were increased firstly and then decreased with dietary CHO ∶L ratio increased,those of CHO ∶L ratio at 1.39 group was the highest,which significantly higher than those of CHO ∶L ratios at 0.54 and 3.50 groups (P＜0.05).2) Dietary CHO ∶L ratio had no significant influences on moisture,crude protein and crude ash contents of juvenile Scylla paramamosain (P＞0.05),but significantly affected the crude lipid content (P＜0.05).The crude lipid content of CHO ∶L ratio at 0.54 group was the highest,which significantly higher than that of CHO ∶L ratios at 2.08 and 3.50 groups (P＜0.05).3) Dietary CHO ∶L ratio had no significant influence on the amylase activity of juvenile Scylla paramamosain (P＞0.05),but significantly affected the protease and lipase activities (P＜0.05).The protease activity was increased firstly and then decreased with dietary CHO ∶L ratio increasing,while the lipases activity was decreased with dietary CHO ∶L ratio increased.The protease activity of CHO ∶L ratio at 1.39 group was significantly higher than that of other groups (P＜0.05),the lipases activity of CHO ∶L ratios at 0.54 and 0.88 groups was significantly higher than that of CHO ∶L ratios at 2.08 and 3.50 groups (P＜0.05).In conclusion,the regression model analysis show that the suitable dietary CHO ∶L ratio to reach the highest weight growth rate of juvenile Scylla paramamosain is 2.07.