Hagerman Fish Culture Experiment Station, Aquaculture Research Institute, University of Idaho, Hagerman, ID, USA; Department of Animal, Veterinary and Food Sciences, Aquaculture Research Institute, University of Idaho, Moscow, ID, USA.
Hagerman Fish Culture Experiment Station, Aquaculture Research Institute, University of Idaho, Hagerman, ID, USA; Department of Aquaculture and Fisheries, University of Ilorin, Ilorin, Nigeria.
Fish Shellfish Immunol. 2021 Feb;109:116-124. doi: 10.1016/j.fsi.2020.12.008. Epub 2020 Dec 19.
Black solider fly larvae (BSFL) and their oils (BSFLO) are receiving increasing attention as sustainable ingredients in fish feeds, but mostly as replacements to marine sources. There were two aims to this study; in exp. 1, soybean meal (SBM)-based diets were formulated to contain BSFL as supplements at 0 (SBM), 8 (SBM + BSFL) or 16% (SBM + BSFL) with a control diet being fishmeal-based (FM). In exp. 2, diets included only fish oil (FO), soybean oil (SBO), BSFLO or BSFLO + bile acid (BA), and all lipid sources were added at 16%. Both experiments were run at the same time and fed to rainbow trout (32 g) with each treatment being triplicated. After 10 weeks the fish were sampled for liver and distal intestine histology, expression of genes responsible for inflammation in the intestine and kidneys, and serum peroxidase and lysozyme activities. In exp. 1, supplementations of BSFL effectively prevented SBM-induced intestinal enteritis, down-regulated intestinal prostaglandin and interferon regulatory factor 1 (IRF-1), while the SBM + BSFL diet significantly increased serum lysozyme activity. In exp. 2, BSFLO caused no histomorphological change to the liver or intestine, but kidney interluekin-8, tumor necrosis factor and IRF-1 were significantly upregulated along with significantly higher serum peroxidase activity. The inclusion of BA in the BSFLO diets significantly upregulated intestinal prostaglandin gene expression. Overall, BSFL supplementations of 8 or 16% prevented SBM-induced intestinal enteritis based on histological observations, which was supported by a down-regulation in pro-inflammatory genes and enhanced innate immunity. Meanwhile, the use of BSFLO showed some immunological benefits. Therefore, these sustainable resources are recommended in the diets of rainbow trout, especially when using elevated levels of plant-based proteins.
黑水虻幼虫（BSFL）及其油脂（BSFLO）作为鱼类饲料中的可持续成分，越来越受到关注，主要是作为海洋来源的替代品。本研究有两个目的；在实验 1 中，配制了基于大豆粉（SBM）的饲料，其中包含 0（SBM）、8（SBM+BSFL）或 16%（SBM+BSFL）的 BSFL 作为补充，对照饲料为基于鱼粉（FM）的饲料。在实验 2 中，饲料仅包含鱼油（FO）、大豆油（SBO）、BSFLO 或 BSFLO+胆汁酸（BA），所有脂质来源均添加 16%。两个实验同时进行，用 32 克虹鳟鱼进行喂养，每个处理重复 3 次。10 周后，对鱼进行肝脏和远端肠道组织学采样，检测肠道和肾脏中负责炎症的基因表达，以及血清过氧化物酶和溶菌酶活性。在实验 1 中，BSFL 的补充有效地预防了 SBM 引起的肠道肠炎，下调了肠道前列腺素和干扰素调节因子 1（IRF-1），而 SBM+BSFL 饮食显著增加了血清溶菌酶活性。在实验 2 中，BSFLO 对肝脏或肠道没有引起组织形态学变化，但肾脏白细胞介素-8、肿瘤坏死因子和 IRF-1 显著上调，同时血清过氧化物酶活性显著升高。BA 包含在 BSFLO 饮食中，显著上调了肠道前列腺素基因的表达。总体而言，8%或 16%的 BSFL 补充剂可预防 SBM 引起的肠道肠炎，这一结果得到了促炎基因下调和增强的固有免疫的支持。同时，BSFLO 的使用显示出一些免疫益处。因此，建议在虹鳟鱼的饮食中使用这些可持续资源，特别是在使用高水平植物性蛋白时。
