果寡糖对斜带石斑鱼免疫功能和肠道形态的影响

Effects of Fructooligosaccharide on Immune Function and Intestinal Morphology of Grouper Epinephelus coioides

以初始体质量(18.13±0.02)g的斜带石斑鱼为试验对象,探讨果寡糖对石斑鱼免疫功能和肠道形态的影响。试验分为4组:基础饲料组(对照组),及3个分别在对照组基础上添加质量分数为0.05%、0.10%以及0.20%果寡糖的试验组。每组3个平行,每个平行25尾鱼,试验周期56 d。试验结果表明,饲料中添加不同剂量的果寡糖能够改善石斑鱼免疫功能,饲养28 d时,0.10%试验组和0.20%试验组超氧化物歧化酶活性、0.05%试验组溶菌酶活性、3个试验组酸性磷酸酶活性均显著高于对照组(P<0.05),而试验组碱性磷酸酶活性与对照组无显著性差异。饲养56 d时,0.10%试验组超氧化物歧化酶活性、0.20%试验组酸性磷酸酶活性显著高于对照组(P<0.05)。饲料中添加不同剂量的果寡糖能够改善幼鱼肠道形态,28 d时,0.05%试验组和0.20%试验组绒毛高度、0.10%试验组肌层厚度、3个试验组绒毛宽度均显著高于对照组(P<0.05);56 d时,0.05%试验组绒毛高度、0.10%试验组肌层厚度、3个试验组绒毛宽度均显著高于对照组(P<0.05)。饲料中添加0.05%~0.20%果寡糖能改善斜带石斑鱼的免疫功能和肠道形态。

Juvenile grouper Epinephelus coioides with initial body weight of(18.13±0.02)g were reared in tanks of each 75 cm×45 cm×50 cm at stocking density of 25 fish per tank and fed diets supplemented with fructooligosaccharide(FOS)levels of 0(control group,group T1),0.05%(group T2),0.10%(group T3)and 0.20%(group T4)at water temperature of 25—29℃for 56 days with triplication to evaluate the effects of FOS on immune function and intestinal morphology of the grouper.The results showed that dietary supplementation of FOS led to improve the immune response of the grouper.There were significantly higher activities of serum superoxide dismutase(SOD)in groups T3 and T4,lysozyme(LSZ)in group T2,and acid phosphatase(ACP)in groups T2,T3 and T4 than those in the control group at day 28(P<0.05).The serum SOD activity in group T3,and serum ACP activity in group T4 were found to be significantly higher than those in the control group at day 56(P<0.05).The intestinal morphology of the grouper was influenced by dietary FOS supplementation,with significantly higher intestinal villus height in group T2 at days 28 and 56,and intestinal villus width in all experimental groups at days 28 and 56,and significantly higher intestinal muscle thickness in group T3 at days 28 and 56 than those in the control group(P<0.05).In conclusion,dietary supplementation of 0.05%—0.20%of FOS resulted in improvement of the immune response and intestinal morphology of the grouper.