蝉花菌质(Isaria cicadae)对大黄鱼(Larimichthys crocea)幼鱼生长、免疫和肠道菌群的影响

试验目的旨在研究蝉花菌质(Isaria cicadae)对大黄鱼(Larimichthys crocea)幼鱼生长性能、抗氧化和免疫、肠道组织形态以及肠道菌群等方面的影响,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(16.50±1.10) g的大黄鱼幼鱼随机分成4组,对照组(IC0)不添加蝉花菌质,试验组分别添加1%(IC1)、3%(IC3)和5%(IC5)的蝉花菌质。试验结果表明:试验组的增重率(WGR)和特定生长率(SGR)显著高于对照组(P<0.05)。IC3与IC5组的肝体比(HSI)显著低于对照组(P<0.05),与IC1组差异不显著(P>0.05)。IC5组脏体比(VSI)显著低于对照组,但与其他试验组之间差异不显著(P<0.05)。肌肉和全鱼体成分各组之间差异不显著(P>0.05)。试验组肝脏过氧化氢酶(CAT)和血清溶菌酶(LZM)的活性显著高于对照组(P<0.05),各试验组间无显著性差异(P>0.05)。对照组单根绒毛杯状细胞数量显著少于各试验组(P<0.05),各试验组间无显著性差异(P>0.05...

EFFECTS OF ISARIA CICADAE ON GROWTH, IMMUNITY, AND INTESTINAL FLORA OF JUVENILE LARGE YELLOW CROAKER (LARIMICHTHYS CROCEA)

To understand the effects of Isaria cicadae on the growth performance, antioxidant and immunity, intestinal tissue morphology, and intestinal flora of juvenile large yellow croaker (Larimichthys crocea), and to provide a green feed additive for large yellow croaker. Fishes in initial body weight of (16.50±1.10) g were randomly divided into 4 groups for study. Fish were fed basal diet (IC0, the control group), basal diet +1% I. cicadae (IC1 group), basal diet +3% I. cicadae (IC3 group) and basal diet +5% I. cicadae (IC5 group) respectively. Results showed that the weight gain rate (WGR) and special growth rate (SGR) of experiment groups were significantly higher than those of control group (P<0.05). The hepatosomatic index (HSI) of IC3 and IC5 groups was significantly lower than that of the control group (P<0.05), but there was no significant difference from that of IC1 group (P>0.05). The viscerosomatic index (VSI) of IC5 group was significantly lower than the control group, but there was no significant difference from other experimental groups (P<0.05). The activity of liver catalase (CAT) and lysozyme (LZM) in the experiment groups was significantly higher than the control group (P<0.05), and there was no significant difference among the experiment groups (P>0.05). In the intestinal structure, there was no significant difference in thickness, fold height, and lamina propria width among all the groups (P>0.05), the number of single villous goblet cells in the experiment groups was significantly greater than the control group (P<0.05), and there was no significant difference among experiment groups (P>0.05). The abundance of intestinal flora in IC0 and IC1 groups was significantly higher than IC3 and IC5 groups (P<0.05). At phylum level, the dominant flora in all groups were Firmicutes and Proteobacteria; at genus level, Bacteroides was more abundant in the control group, and the beneficial bacteria Bacillus was more abundant in the experiment groups. In conclusion, I. cicadae could promote the growth, improve the antioxidant and immunity ability, improve the intestinal tissue morphology, increase the amount of Bacillus in the intestines of juvenile large yellow croaker.