饲料可消化糖水平对宝石鲈餐后代谢的影响

Effects of dietary digestible carbohydrate level on postprandial metabolism of Jade perch Scortum barcoo

以含可消化糖水平为0%、6%、23%和40%的等蛋白、等脂肪饲料饲养宝石鲈(Scortum barcoo)6周,禁食36h后饱食投喂,测定不同时间段血液指标及肝肌糖元的变化。结果表明,投喂Ⅱ组(23%)饲料的宝石鲈生长及饲料利用状况最佳;摄食后血糖、甘油三酯和胆固醇均为先上升后下降,随可消化糖水平升高,血糖和甘油三酯上升幅度显著增大(P<0.05),总胆固醇上升幅度依次减小,总氨基酸无明显变化;肝糖元除Ⅲ组(40%)外均呈先上升后下降的趋势,肌糖元先上升后下降,最后维持稳定。肝肌糖元含量上升幅度均随可消化糖水平升高而增大。结果显示在饲料可消化糖水平为23%时,宝石鲈的生长及饲料利用状况最佳,过高的可消化糖会对机体产生一定生理负荷及胁迫作用,影响其生长及代谢状况。

Jade perches （Scortum barcoo） were fed with iso-protein and iso-lipid experimental diets at digestible carbohydrate levels of 0% （ control group）, 6% （ group I ）, 23% （ group II ） and 40% （ group m ） for 6 weeks. After 36-hour fasting, the blood biochemical indices and contents of liver and muscle glycogens were examined at 0, 3, 6, 12, 24 and 36 h, respectively. The results showed that the growth performance and feed utilization of group II （23%） were the best. Contents of plasma glucose, triglyeeride and total cholesterol all increased firstly and then decreased after feeding ; plasma glucose and triglyceride increased significantly fast （ P 〈 0. 05 ） with increasing digestible carbohydrate level in diets, while total cholesterol decreased gradually; total amino did not change obviously. Liver glycogen content （ except for group III ） increased firstly and then decreased after feeding; muscle glycogen decreased firstly, then increased gradually and finally remained stable. Contents of liver and muscle glycogens increased faster with increasing level of digestible carbohydrate. The results indicated that the growth performance and feed utilization of Jade perch at 23% digestible carbohydrate achieved the best effect. Exorbitant digestible carbohydrate could cause physiological load and stress for the organism, which would be harmful to the growth and metabolism of the fish.