In this study, the different dosage of laminarin groups (normal fodder group (Control), normal fodder add 1 g laminarin group (AL1), normal fodder add 2 g laminarin group (AL2), normal fodder add 4 g laminarin group (AL4) and normal fodder add 8 g laminarin group (AL8)) were set. After 45 days, the growth, enzyme activity and immune-related gene were measured to assess the effect of feeding laminarin on Ictalurus punctatus. Laminarin (4 g dosage) can significantly increase body length (p < .05) and BMI (body mass index) value in 8 g dosage group (p < .05). Lysozyme, acid phosphatase, aspartate aminotransferase, catalase, superoxide dismutase, pepsin, amylase and trypsin activity are increased with the dosage of laminarin increasing, and have a significant difference at the dosage of 4 g and 8 g group (p < .001). However, the serum cortisol content, alkaline phosphatase and lipase activity have a significant inhibition in high-dosage groups (p < .001). The expression of TLR5 gene in group of 4 g dosage was significantly upregulated (p < .05). The expression of SOCs gene in groups of 2 g (p < .05), 4 g (p < .001) and 8 g (p < .001) dosage was significantly downregulated. The expression of IGF2 and STAT5 genes was significantly upregulated in high-dosage laminarin groups. Generally, larminarin enhances the immune response, reduces the rate of energy decomposition required and improves food absorption. This shows that the larminarin improves the physical quality and increases productivity of I. punctatus, and offers great potential for application in the aquaculture industry.

中文翻译：

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膳食海带多糖增强免疫反应、促进生长和增强体质

本研究中不同用量的海带多糖组(普通饲料组(Control)、普通饲料添加1g海带多糖组(AL1)、普通饲料添加2g海带多糖组(AL2)、普通饲料添加4g海带多糖组(AL4)和正常饲料添加8g海带多糖组（AL8））。45天后，测定生长、酶活性和免疫相关基因，以评估饲喂海带多糖对点状鱼的影响。海带多糖（4 g 剂量）可显着增加 8 g 剂量组的体长（p < .05）和 BMI（体重指数）值（p < .05）。溶菌酶、酸性磷酸酶、天冬氨酸转氨酶、过氧化氢酶、超氧化物歧化酶、胃蛋白酶、淀粉酶和胰蛋白酶的活性随着海带多糖用量的增加而增加，4 g和8 g组有显着差异（p  < .001）。然而，血清皮质醇含量、碱性磷酸酶和脂肪酶活性在高剂量组中具有显着抑制作用 ( p  < .001)。4g剂量组TLR5基因表达显着上调（p  <.05）。SOCs基因在2 g ( p  < .05)、4 g ( p  < .001)和8 g ( p < .001) 剂量显着下调。IGF2 和 STAT5 基因的表达在高剂量海带多糖组中显着上调。通常，海藻多糖可增强免疫反应，降低所需的能量分解速度并改善食物吸收。这表明海藻多糖改善了I的物理质量并提高了生产率。punctatus，并为水产养殖业提供了巨大的应用潜力。