鞣花酸对大口黑鲈生长与肠道健康的影响

Effects of Ellagic Acid on Growth and Intestinal Health of Largemouth Bass ( Micropterus salmoides )

本试验旨在探究鞣花酸对大口黑鲈生长与肠道健康的影响。选取初始体重为(59.17±0.06)g的大口黑鲈450尾,随机分成5个组,每组3个重复,每个重复30尾。各组分别投喂鞣花酸添加水平为0(对照组)、0.01%(EA1组)、0.02%(EA2组)、0.03%(EA3组)、0.04%(EA4组)的5种等氮等脂试验饲料。试验期为56 d。结果表明:1)EA4组的终末体重、增重率和特定生长率显著高于对照组(P<0.05)。各组之间肝体比、肥满度、饲料系数、摄食率和存活率无显著差异(P>0.05)。2)各组之间全鱼水分、粗灰分、粗蛋白质、粗脂肪含量及肝脏粗脂肪含量无显著差异(P>0.05)。3)各组之间血清补体3、补体4含量和酸性磷酸酶、溶菌酶活性无显著差异(P>0.05)。EA4组的血清碱性磷酸酶活性显著高于对照组(P<0.05)。4)各组之间肠道胰蛋白酶、脂肪酶和淀粉酶活性无显著差异(P>0.05)。5)与对照组相比,试验组的肠道绒毛高度、绒毛宽度和绒毛数量均有所增长,且排列更为紧密。6)与对照组相比,EA1、EA2和EA4组的肠道梭杆菌门相对丰度显著升高(P<0.05),EA2和EA4组的肠道支原体属相对丰度显著降低(P<0.05),EA1、EA2和EA4组的肠道鲸杆菌属相对丰度显著升高(P<0.05)。综上所述,饲料中添加鞣花酸可有效提高大口黑鲈的生长性能,改善肠道组织结构,在降低有害菌相对丰度的同时提高有益菌相对丰度,保护肠道健康。以增重率和特定生长率为评价依据,大口黑鲈饲料中鞣花酸的适宜添加水平为0.04%。

The objective of this study was to investigate the effect of ellagic acid on growth and intestinal health of largemouth bass(Micropterus salmoides).A total of 450 largemouth bass with an initial body weight of(59.17±0.06)g were randomly selected and divided into 5 groups with 3 replicates in each group and 30 fish in each replicate.Fish in 5 groups were fed five kinds of equal nitrogen and equal fat experimental diets which the ellagic acid supplemental levels were 0(control group),0.01%(EA1 group),0.02%(EA2 group),0.03%(EA3 group)and 0.04%(EA4 group),respectively.The experiment lasted for 56 days.The results showed as follows:1)the final body weight,weight gain rate and specific growth rate of EA4 group were significantly higher than those of the control group(P<0.05).There were no significant differences in hepatopancreas somatic index,condition factor,feed conversion ratio,feeding rate and survival rate among all groups(P>0.05).2)There were no significant differences in whole fish moisture,crude ash,crude protein and ether extract contents and liver ether extract content among all groups(P>0.05).3)There were no significant differences in serum complement 3,complement 4 contents and acid phosphatase,lysozyme activities among all groups(P>0.05).4)There were no significant differences in activities of trypsin,lipase and amylase in intestine among all groups(P>0.05).5)Compared with the control group,the intestinal villus height,villus width and villus number of experimental groups were increased,and the arrangement was closer.6)Compared with the control group,the intestinal Fusobacteriota relative abundance of EA1,EA2 and EA4 groups was significantly increased(P<0.05),the intestinal Mycoplasma relative abundance of EA2 and EA4 groups was significantly decreased(P<0.05),and the intestinal Cetobacterium relative abundance of EA1,EA2 and EA4 groups was significantly increased(P<0.05).In conclusion,the addition of ellagic acid in the diet can effectively improve the growth performance of largemouth bass,improve the intestinal tissue structure,reduce the relative abundance of harmful bacteria and increase the relative abundance of beneficial bacteria,thereby promoting intestinal health.Based on the weight gain rate and specific growth rate,the suitable supplemental level of ellagic acid in diet for largemouth bass is 0.04%.