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

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40d。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≤0.05）,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%）。

Influence of Different Dietary Soybean Lecithin / Fish Oil Ratios on Growth Performance and Histology of Juvenile Grouper Epinephelus coioides

Four formulated microdiets supplemented with different soybean lecithin/fish oil （SL/FO） ratios： Diet1（0%/22% ） ,Diet2（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 0. 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% ） .