The present study was to investigate the effect of dietary Tribonema ultriculosum supplementation on growth performance, fillet nutritional quality and immunity of rainbow trout Oncorhynchus mykiss (165.26 ± 0.57 g, mean ± SD). Three diets containing 0 (control), 50 g/kg and 100 g/kg T. ultriculosum (TU) were introduced to triplicate groups of the experimental fish for 90 days. Then, a lipopolysaccharide (LPS) stress experiment was conducted to evaluate the effect of microalgal addition on fish immune response. Compared to the control, microalgal addition significantly increased fish feed intake and growth. Dietary T. ultriculosum supplementation significantly increased the contents of palmitoleic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid in fillet. The addition of T. ultriculosum significantly increased the activity levels of spleen glutathione peroxidase (before LPS stress) and superoxide dismutase (after LPS stress), and simultaneously decreased the spleen malondialdehyde content compared to the control. In terms of the immune response, fish fed diets containing T. ultriculosum had a higher level of lysozyme activity (before LPS stress), immunoglobulin M content (before and after LPS stress) and hepcidin expression (after LPS stress) compared to the control. These results suggest that T. ultriculosum can be used to increase fish growth, fillet nutritional quality and immunity.

中文翻译：

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日粮添加丝状微藻 Tribonema ultriculosum 对虹鳟鱼生长性能、鱼片品质和免疫力的影响

本研究旨在研究日粮添加Tribonema ultriculosum对虹鳟Oncorhynchus mykiss (165.26 ± 0.57 g, mean ± SD)生长性能、鱼片营养品质和免疫力的影响。含有 0（对照）、50 g/kg 和 100 g/kg T 的三种饮食。 ultriculosum (TU) 被引入实验鱼的三组重复 90 天。然后，进行脂多糖（LPS）应激实验以评估添加微藻对鱼类免疫反应的影响。与对照相比，添加微藻显着增加了鱼的采食量和生长。饮食T。 榆钱鱼片中棕榈油酸、二十碳五烯酸 (EPA) 和二十二碳六烯酸的含量显着增加。添加T。 与对照相比，ultriculosum显着增加了脾谷胱甘肽过氧化物酶（LPS 应激前）和超氧化物歧化酶（LPS 应激后）的活性水平，同时降低了脾中丙二醛的含量。在免疫反应方面，鱼喂食含有T 的饮食。 与对照相比，ultriculosum具有更高水平的溶菌酶活性（LPS 应激之前）、免疫球蛋白 M 含量（LPS 应激之前和之后）和铁调素表达（LPS 应激之后）。这些结果表明T . 榆钱 可用于增加鱼的生长、鱼片的营养品质和免疫力。