蝉花菌质对大黄鱼生长性能、肝脏抗氧化能力和肠道菌群的影响

Effects of Isaria cicadae Spent Mushroom Substrate on Growth,Liver Antioxidant Capacity and Intestinal Microflora of Large Yellow Croaker(Larimichthys crocea)

本试验旨在研究蝉花菌质对大黄鱼生长性能、肝脏抗氧化能力、血清免疫能力、肠道形态和肠道菌群的影响,为大黄鱼绿色饲料添加剂的开发和利用提供参考。将初始体重为(273.07±14.90)g的180尾大黄鱼随机分为3组,每组3个网箱,每个网箱20尾。3组试验鱼分别投喂基础饲料(IC0组,作为对照组)、基础饲料+2%蝉花菌质(IC2组)、基础饲料+6%蝉花菌质(IC6组)。养殖周期为56 d。结果表明:1)IC6组的增重率(WGR)、特定生长率(SGR)和饲料效率(FE)显著高于IC0组(P<0.05);IC2组的肝体比(HSI)和脏体比(VSI)显著高于IC0和IC6组(P<0.05);各组间存活率无显著差异(P>0.05)。2)与IC0组相比,IC2组肌肉和全鱼粗脂肪含量显著提高(P<0.05),肌肉水分含量显著下降(P<0.05);而IC6组肌肉和全鱼粗脂肪含量显著下降(P<0.05),水分含量显著提高(P<0.05)。3)与IC0组相比,IC6组肝脏总超氧化物歧化酶(T-SOD)和过氧化氢酶(CAT)活性显著提高(P<0.05);IC2组肝脏过氧化氢酶(CAT)活性显著提高(P<0.05),肝脏谷胱甘肽过氧化物酶(GSH-Px)活性显著降低(P<0.05);各组间肝脏丙二醛(MDA)含量以及血清补体3(C3)、补体4(C4)含量与溶菌酶(LZM)、谷丙转氨酶(ALT)和谷草转氨酶(AST)活性均无显著差异(P>0.05)。4)IC6组肠道单根绒毛杯状细胞数量显著高于IC0和IC2组(P<0.05)。5)与IC0组相比,IC6组的Simpson和Shannon指数显著上升(P<0.05),IC2组的Shannon指数显著上升(P<0.05)。在门水平上,与IC0组相比,IC2和IC6组变形菌门(Proteobacteria)和放线菌门(Actinobacteriota)相对丰度显著提高(P<0.05),拟杆菌门(Bacteroidota)、脱硫杆菌门(Desulfobacterota)、互养菌门(Synergistota)和绿弯菌门(Chloroflexi)相对丰度显著降低(P<0.05);在属水平上,与IC0组相比,IC6组拟杆菌属(Bacteroides)相对丰度显著提高(P<0.05),IC2组克雷伯氏菌属(Klebsiella)相对丰度显著提高(P<0.05),IC2和IC6组瘤胃杆菌属(Ruminofilibacter)、脱硫菌属(Desulfomicrobium)和氨基杆菌属(Aminobacterium)相对丰度显著降低(P<0.05)。综上所述,饲料中添加蝉花菌质有利于改善大黄鱼的生长性能、抗氧化能力和肠道菌群结构,以6%的添加量效果较好。

This study was conducted to investigate the effects of Isaria cicadae spent mushroom substrate on growth performance,liver antioxidant capacity,serum immunity,intestinal morphology and intestinal microflora of large yellow croaker(Larimichthys crocea),and to provide reference for the development and utilization of green feed additives for large yellow croaker.A total of 180 large yellow croaker with an initial body weight of(273.07±14.90)g were randomly divided into 3 groups with 3 cages in each group and 20 fish in each cage.Fish in the 3 groups were fed a basal diet(IC0 group,as control group)and the basal diet supplemented with 2%(IC2 group)and 6%(IC6 group)of Isaria cicadae spent mushroom substrate,respectively.The experiment lasted for 56 days.The results showed as follows:1)the weight gain rate(WGR),specific growth rate(SGR)and feed efficiency(FE)in IC6 group were significantly higher than those in IC0 group(P<0.05);the hepatosomatic index(HSI)and viscerosomatic index(VSI)in IC2 group were significantly higher than those in IC0 and IC6 groups(P<0.05);there was no significant difference in survival rate(SR)among all groups(P>0.05).2)Compared with the control group,the ether extract content of muscle and whole fish in IC2 group was significantly increased(P<0.05),and moisture content of muscle was significantly decreased(P<0.05);the ether extract content of muscle and whole fish in IC6 group was significantly decreased(P<0.05),and the moisture content was significantly increased(P<0.05).3)Compared with the control group,the activities of liver total superoxide dismutase(T-SOD)and catalase(CAT)in IC6 group were significantly increased(P<0.05);the activity of liver CAT in IC2 group was significantly increased(P<0.05),and the activity of liver glutathione peroxidase(GSH-Px)was significantly decreased(P<0.05);there were no significant differences in the content of malondialdehde(MDA)in liver,the contents of complement 3(C3),complement 4(C4),and the activities of lysozyme(LZM),alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in serum among all groups(P>0.05).4)The number of gobletcells per villus of intestine in IC6 group was significantly higher than that in IC0 and IC2 groups(P<0.05).5)Compared with IC0 group,the Simpson index and Shannon index of IC6 group were significantly increased(P<0.05),the Shannon index of IC2 group was significantly increased(P<0.05).At the phylum level,compare with IC0 group,the relative abundances of Proteobacteria and Actinobacteriota were significantly improved in IC2 and IC6 groups(P<0.05),while the relative abundances of Bacteroidota,Desulfobacterota,Synergistota and Chloroflexi were significantly decreased in IC2 and IC6 groups(P<0.05).At the genus level,compared with IC0 group,the relative abundance of Bacteroides was significantly improved in IC6 group(P<0.05),the relative abundance of Klebsiella was significantly improved in IC2 group(P<0.05),and the relative abundances of Ruminofilibacter,Desulfomicrobium and Aminobacterium were significantly decreased in IC2 and IC6 groups(P<0.05).In conclusion,the growth performance,antioxidant capacity and intestinal microflora structure of large yellow crook can be improved by adding Isaria cicadae spent mushroom substrate in the diet,and the effect of 6%is better.