饲料碳水化合物水平对拟穴青蟹稚蟹生长、体成分和消化酶活性的影响

EFFECTS OF DIETARY CARBOHYDRATE LEVEL ON GROWTH PERFORMANCE, BODY COMPOSITION AND DIGESTIVE ENZYME ACTIVITIES OF JUVENILE CRAB,SCYLLA PARAMAMOSAIN

用碳水化合物水平分别为20.34%、25.59%、30.17%、35.30%和39.95%的5种等氮等脂饲料,对初始体质量为(38.11±0.55) mg的拟穴青蟹(Scylla paramamosain)稚蟹进行3周的饲养试验,探讨饲料不同碳水化合物水平对稚蟹生长、体成分和消化酶活性的影响,以期确定拟穴青蟹稚蟹饲料碳水化合物的适宜需要量。结果表明,不同碳水化合物水平饲料对拟穴青蟹稚蟹的成活率、生长均有显著影响(P<0.05),均随碳水化合物水平的升高先显著增大(P<0.05)后显著减小(P<0.05),均在碳水化合物水平为30.17%时达到最大值;随着饲料碳水化合物水平的升高,拟穴青蟹稚蟹的蛋白质和灰分含量也呈先显著升高(P<0.05)后显著降低(P<0.05)的趋势,均在碳水化合物水平为35.30%时达到最大值,而稚蟹的水分和脂肪含量没有显著变化(P>0.05);不同碳水化合物水平饲料组拟穴青蟹稚蟹的蛋白酶和脂肪酶活性的变化不显著(P>0.05),而淀粉酶活性有显著变化(P<0.05),高碳水化合物水平饲料组(35.30%—39.95%)稚蟹的淀粉酶活性显著高于低碳水化合物水平饲料组(20.34%—25.59%,P<0.05)。在研究条件下,饲料碳水化合物水平在25.59%—35.30%内,拟穴青蟹稚蟹均表现出较好的生长率,增重率和碳水化合物水平的回归分析表明,稚蟹饲料碳水化合物的最适添加水平为29.93%。

To investigate the effects of dietary carbohydrate on growth performance,body composition and digestive enzyme activities of juvenile crab,Scylla paramamosain,five isonitrogenous and isolipidic diets with varying carbohydrate contents of 20.34%,25.59%,30.17%,35.30%and 39.95%were fed to juvenile crabs with an average body weight of(38.11±0.55)mg of triplicate groups,respectively,for a 3-week feeding trial.Results showed that the survival rate,weight gain ratio and specific growth rate of the juvenile crabs significantly increased firstly and then decreased under the increased dietary carbohydrate level(P<0.05)with the highest level at 30.17%.With the increasing dietary carbohydrate level,the body crude protein and body ash contents of the crabs were significantly increased firstly and then decreased(P<0.05)with the highest level at 35.30%.Dietary carbohydrate level significantly affected amylase activity(P<0.05)without any significant influence on protease and lipase activities(P>0.05).The amylase activity significantly induced by high carbohydrate level(P<0.05).These results indicate that the diet with 25.59%-35.30%carbohydrate could greatly support growth performance.The regression model analysis showed that the most suitable dietary carbohydrate level reach the highest weight gain ratio is 29.93%.