饲料中大豆卵磷脂/鱼油比例对斜带石斑鱼稚鱼生长发育及肠道组织的影响

摘要

Four formulated microdiets supplemented with different soybean lecithin / fish oil (SL/FO) ratios:Diet 1 (0％/22％),Diet 2 (5％/14％),Diet 3 (10％/8％) and Diet 4 (15％/7％) were fed to 40-day-old juvenile grouper Epinephelus coioides after hatching.Each experimental diet was distributed in triplicate tanks.The survival,feed efficiency,growth performance and intestine histology of the grouper juveniles were monitored after a 40-day growth trial.Results showed that different dietary SL/FO ratios significantly affected the growth and survival (P ≤0.05) of the grouper juveniles.The juveniles fed Diet 3 (10％/8％,SL/FO) and Diet 4 (15/7,SL/FO) gave significantly higher weight gain (WG) than those fed Diet 1 (0％/22％,SL/FO).The juveniles fed Diet1 (0％/22％,SL/FO) had obviously lower whole body lipid content than those fed other diets (P≤0.05),but had significantly higher whole body protein content than those fed other diets (P ＜ O.05).For all treatments no significant differences were observed in feed efficiency (FE),hepatosomatic index (HSI),viscerosomatic index (VSI) and condition factor (CF),specific growth rate (SGR),feed intake (FI),protein efficiency ratio (PER),and final body weight (FBW).Increase in dietary soybean lecithin/fish oil (SL/FO) ratio reduced lipid droplets in intestine enterocytes of grouper juvenile.It is concluded that the grouper juvenile microdiets should have a high dietary soybean lecithin/fish oil ratio (15％/7％).%为探讨饲料中不同大豆卵磷脂/鱼油比例对斜带石斑鱼稚鱼成活率、生长行为、饲料利用以及肠道组织学的影响,本实验设计了4种添加不同大豆卵磷脂/鱼油比率的微颗粒饲料:0％/22％(饲料1),5％/14％(饲料2),10％/8％(饲料3)以及15％/7％(饲料4),饲喂斜带石斑鱼稚鱼.每种实验饲料均设3个平行.试验持续40 d.结果表明,饲料中不同大豆卵磷脂/鱼油比例对斜带石斑鱼稚鱼生长以及成活率有显著影响(P≤0.05).饲料3和饲料4的增重分别为:(449.6±11.4)g和(588.3±61.7)g,显著高于饲料1的数值(185.0±2.5)(P≤0.05).饲料1鱼体脂肪含量为:(154.7±12.8)g·kg-1,显著低于其他饲料组(P≤O.05),但其鱼体蛋白含量为(728.3±25.5)g·kg-1,显著高于其他饲料组.饲料效率、肥满度、特定生长率、摄食量和蛋白质效率以及终末体重中,4种饲料之间无显著性差异.随饲料卵磷脂/鱼油比例升高,石斑鱼稚鱼肠道脂滴生成数量出现下降,且在饲料4中未观察到肠道脂滴.研究表明斜带石斑鱼稚鱼生长发育阶段需要较高的饲料卵磷脂/鱼油比例(如:15％/7％).