The current trial investigated the roles of β-carotene and phycocyanin extracted from Spirulina platensis on growth, serum biochemical, digestive enzymes, antioxidant defense, immune responses, and immune gene expression in Nile tilapia (Oreochromis niloticus). Fish (1.52 ± 0.10 g) were randomly stocked to three treatments with three replicates (12 fish per replicate) in nine aquaria (60 L glass aquarium for each), and reared for 70-days. Three tested diets were formulated to be isonitrogenous and isolipidic, and were offered for experimental fish until ad-libitum three times daily at 09:00 a.m., 11.00 a.m. and 3:00 p.m. The first diet (control) was without supplementation. About 50 mg β-carotene and 50 mg phycocyanin kg⁻¹ were supplemented to the other experimental diets, respectively. Results indicated that feed intake was not (P > 0.05) differ among experimental diets. Compared to control diet wight gain and specific growth rate were significantly (P < 0.05) in fish fed diet containing β-carotene, while, the highest weight gain and the best FCR were detected in phycocyanin diet. Survival fish among treatments was significantly (P < 0.05) differ and the highest survival rate was showed in fish fed diet supplemented with phycocyanin. Either β-carotene or phycocyanin significantly (P < 0.05) improved the intestinal digestive enzymes compared with control diet, where the highest values of chymotrypsin, trypsin, lipase and amylase were noticed in fish fed phycocyanin. Diets supplemented with β-carotene and phycocyanin significantly (P < 0.05) improved hematology parameters contents compared with to the control diet, and the best contents were detected in fish fed diet supplemented with phycocyanin. The highest significant (P < 0.05) phagocytic, lysozyme, immunoglobulin M (IgM), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and total antioxidant capacity (T-AOC) activities were recorded in diet supplemented with phycocyanin. The transcripts of interferon gamma and interleukin 1β genes were (P < 0.05) up-regulated in the liver of fish fed diet supplemented with β-carotene and phycocyanin, but expression of HSP70 gene down-regulated in fish fed β-carotene and phycocyanin containing diet compared control. The highest gene expression of the interferon gamma and interleukin 1β was observed in fish fed phycocyanin.

本试验研究了从螺旋藻中提取的β-胡萝卜素和藻蓝蛋白对尼罗罗非鱼（Oreochromis niloticus）生长，血清生化，消化酶，抗氧化防御，免疫反应和免疫基因表达的作用。将鱼（1.52±0.10 g）随机放养到三个处理中，在九个水族箱（每个60 L玻璃水族箱）中进行三重复（每重复12条鱼），并饲养70天。三种经测试的日粮配制为等氮和等脂饮食，并提供给实验鱼，直到每天09:00 am，11.00 am和3:00 pm任意采食3次为止。第一种饮食（对照）无需补充。约50 mgβ-胡萝卜素和50 mg藻蓝蛋白kg ^-1分别补充其他实验饮食。结果表明，实验饮食之间的采食量没有差异（P> 0.05）。与对照组相比，含β-胡萝卜素的鱼饲料的日增重和比生长速率显着（P <0.05），而藻蓝蛋白日粮中增重最高，FCR最好。各处理之间的存活鱼有显着差异（P <0.05），并且饲喂补充藻蓝蛋白的鱼的存活率最高。与对照饮食相比，β-胡萝卜素或藻蓝蛋白均显着改善了肠道消化酶（P <0.05），在饲喂鱼蓝藻中，胰凝乳蛋白酶，胰蛋白酶，脂肪酶和淀粉酶的含量最高。日粮中明显补充了β-胡萝卜素和藻蓝蛋白（P <0。05）与对照组相比，血液学参数含量有所提高，在补充藻蓝蛋白的鱼饲料中检测到最佳含量。在补充藻蓝蛋白的饮食中，吞噬，溶菌酶，免疫球蛋白M（IgM），超氧化物歧化酶（SOD），过氧化氢酶，谷胱甘肽过氧化物酶（GPx）和总抗氧化能力（T-AOC）活性最高（P <0.05）。干扰素γ和白细胞介素1β基因的转录本为（补充藻蓝蛋白的饮食中记录了谷胱甘肽过氧化物酶（GPx）和总抗氧化能力（T-AOC）活性。干扰素γ和白细胞介素1β基因的转录本为（补充藻蓝蛋白的饮食中记录了谷胱甘肽过氧化物酶（GPx）和总抗氧化能力（T-AOC）活性。干扰素γ和白细胞介素1β基因的转录本为（ 补充β-胡萝卜素和藻蓝蛋白的鱼饲料的肝脏中P <0.05）上调，但与β-胡萝卜素和藻蓝蛋白的鱼饲料相比，HSP70基因的表达下调。在饲喂藻蓝蛋白的鱼中观察到了干扰素γ和白介素1β的最高基因表达。