为了研究饲料中黑水虻虫粉替代鱼粉对杂交鳢[斑鳢(Channa maculate，♀)×乌鳢(C. argus，♂)]免疫抗氧化、肠道菌群和抗病力的影响。实验采用黑水虻虫粉 (black soldier fly larvae meal, BSFLM)分别替代基础配方中鱼粉的7.5% (BSFLM7.5)、15.0% (BSFLM15)、22.5% (BSFLM22.5)和30.0% (BSFLM30) (对应添加48.8、97.6、146.4和195.2 g/kg的BSFLM干物质)配制5种等氮等脂的饲料。选取525尾均重为 (10.84±0.01) g的杂交鳢，随机分成5组，每组3个重复，每个重复35尾，养殖周期为56 d。结果显示，BSFLM22.5和BSFLM30组血清碱性磷酸酶 (AKP)显著高于BSFLM7.5和FM组，BSFLM22.5组丙二醛 (MDA)含量显著低于FM组，各组血清中、过氧化氢酶 (CAT)、超氧化物歧化酶 (SOD)、总抗氧化能力 (T-AOC)、溶菌酶 (LZM)、谷胱甘肽过氧化物酶 (GSH-Px)活性无显著差异。肠道内容物菌群BSFLM15~BSFLM30实验组Sobs、Chao、Ace、Shannon、Simpson指数显著低于FM和BSFLM7.5组，物种多样性减少；衣原体门、变形菌门、螺旋体门、假单胞菌属和罗尔斯通菌属相对丰度实验组低于FM组。BSFLM30组后肠菌群Sobs指数、Chao指数和Ace指数显著高于FM组和其他实验组，厚壁菌门、拟杆菌门、沉积菌属和紫单孢菌属相对丰度增加，各实验组后肠螺旋体门、假单胞菌属和罗尔斯通菌属相对丰度降低。用舒氏气单胞菌感染，BSFLM7.5、BSFLM7.5和BSFLM22.5组的杂交鳢7 d累计死亡率显著低于FM组的。综上所述，黑水虻虫粉部分替代鱼粉可以改善杂交鳢免疫抗氧化能力，调节肠道内容物菌群结构，增强抗舒氏气单胞菌感染的能力，替代量以不超过22.5% (146.4 g/kg)为宜。

Fish meal is a prevalent source of animal protein in aquatic feed, yet its high cost and an import reliance of up to 80% have hindered the sustainable growth of aquaculture in our country. Thus, it is imperative to identify alternative proteins to replace fish meal. This study aimed to assess the impact of substituting fish meal with black soldier fly larvae meal (BSFLM) on the immune antioxidant status, intestinal flora and disease resistance of hybrid snakehead fish. Five isonitrogenous and isolipid diets were formulated, with fish meal replaced by 7.5% (BSFLM7.5), 15.0% (BSFLM15), 22.5% (BSFLM22.5) and 30.0% (BSFLM30) BSFLM, corresponding to 48.8, 97.6, 146.4 and 195.2 g/kg BSFLM, respectively. A total of 525 hybrid snakeheads with an average body weight of (10.84±0.01) g were randomly assigned to 5 groups, each with 3 replicates 35 fish per replicate. The results indicated that the alkaline phosphatase (AKP) activity in the BSFLM30 group was higher than in the BSFLM7.5 and fish meal (FM) groups (P<0.05). The malondialdehyde (MDA) levels in the BSFLM22.5 group were lower than those in the FM group (P<0.05). No significant differences were observed in the activities of lysozyme (LZM), catalase (CAT), superoxide (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px) among all groups (P>0.05). The richness estimators Sobs, Chao, Ace, as well as Shannon and Simpson diversity indices of the intestinal content flora in the BSFLM15-BSFLM30 groups, were lower than those in the FM and BSFLM7.5 groups (P<0.05), indicating a decrease in species diversity. The relative abundance of Chlamydiae, Proteobacteria, Spirochaetes, Ralstonia and Pseudomonas in the experimental groups was lower than in the control group (P>0.05). Conversely, the BSFLM30 group exhibited higher Sobs, Chao, and Ace indices of intestinal flora compared to the FM and other experimental groups (P<0.05). The relative abundance of Bacteroidetes, Firmicutes, Paludibacter and Sedimentibacter was greater in the BSFLM30 group than in the other groups (P>0.05). The relative abundance of Spirochaetes, Proteobacteria and Ralstonia was lower in the experimental group than that in the control group (P>0.05). The mortality rate following Aeromonas schubertii infection was significantly lower in the BSFLM7.5, BSFLM7.5 and BSFLM22.5 groups than in the FM and BSFLM30 groups (P<0.05). In conclusion, dietary supplementation with BSFLM can enhance immune antioxidant capacity, microbial structure of intestinal contents, increase microbial diversity, improve intestinal function, and bolster resistance to A. schubertii infection. However, the replacement levels should not exceed 22.5%.

S 963.7

广东省现代农业产业技术体系创新团队建设项目 (2022KJ115，2023KJ115)