We evaluated the efficacy of mozuku fucoidan supplementation to alternative dietary proteins used in fish meal (FM) replacement to enhance growth, immunity, and stress resistance of Pagrus major. Seven isonitrogenous (45% protein) experimental diets were formulated where diet 1 (D1) was FM-based control diet. Diets 2 to 7 were formulated by replacing 25, 50, and 75% of FM protein with soy protein isolate (SPI) protein, and each replacement level was supplemented without or with fucoidan at 0.4% for diet groups D2 (FM25), D3 (FM25Fu), D4 (FM50), D5 (FM50Fu), D6 (FM75), and D7(FM75Fu), respectively. Each diet was randomly allocated to triplicate groups of fish (4.1 g) for 56 days. Significantly higher weight gain and specific growth rate were observed in fish fed FM50Fu diet group, and it was not differed (P > 0.05) with fish fed FM25Fu diet group. FM-based control diet showed intermediate value, and it was not differed (P > 0.05) with or without fucoidan-supplemented ≤ 50% FM replacement groups and FM75Fu diet group. Significantly lower growth performances were observed in FM75 diet group. At each replacement level, fucoidan-supplemented groups showed nonsignificant improvement of feed utilization performances. Fish fed fucoidan-supplemented diets showed best condition of oxidative and freshwater stress resistance. Lysozyme activity, NBT, and peroxidase activity showed higher (P > 0.05) values in fucoidan-supplemented groups compared with the non-supplemented groups. Catalase activity was significantly lower in FM75Fu diet group. Catalase activity is significantly influenced by the interaction effects of fucoidan and FM replacement level. In conclusion, fucoidan supplementation could increase the efficiency of utilizing SPI (≥ 75%) without any adverse effects on red sea bream performance.

我们评估了替代鱼粉（FM）来增强Pagrus major的生长，免疫力和抗逆性的替代饮食蛋白的Mozuku岩藻依聚糖的功效。配制了七个等氮（蛋白质含量为45％）的实验饮食，其中饮食1（D1）是基于FM的对照饮食。通过用大豆分离蛋白（SPI）蛋白替代FM蛋白的25％，50％和75％来配制2至7日日粮，对于饮食组D2（FM25），D3（D2（FM25），D3（ FM25Fu），D4（FM50），D5（FM50Fu），D6（FM75）和D7（FM75Fu）。将每种饮食随机分配给三组鱼（4.1克），持续56天。饲喂FM50Fu日粮的鱼组体重增加和比生长率显着提高，并且没有差异（P > 0.05）FM25Fu饮食组喂鱼。基于FM的对照饮食显示出中间值，在添加或不添加岩藻依聚糖补充≤50％FM替代组和FM75Fu饮食组的情况下，两者无差异（P> 0.05）。在FM75饮食组中观察到明显较低的生长性能。在每个替代水平上，添加岩藻依聚糖的组均显示出饲料利用率无显着提高。补充岩藻依聚糖的鱼饲料显示出最佳的抗氧化和耐淡水胁迫条件。溶菌酶活性，NBT和过氧化物酶活性较高（P岩藻依聚糖补充组与非补充组相比> 0.05）值。FM75Fu饮食组的过氧化氢酶活性显着降低。岩藻依聚糖和FM替代水平的相互作用影响过氧化氢酶的活性。总之，岩藻依聚糖补充剂可以提高利用SPI的效率（≥75％），而对红鲷鱼的表现没有任何不利影响。