Abstract Six iso‑nitrogenous and isolipid experimental diets were fed to orange-spotted groupers, Epinephelus coioides, and their growth performance, intestinal morphology, immune function and resistance to Vibrio harveyi infection evaluated. Positive controls (FM) were fed fishmeal as the only protein source. Negative controls (Y0) were fed a lower proportion of fishmeal in combination with plant proteins. The other groups were fed the Y0 diet supplemented with Saccharomyces cerevisiae hydrolysate at proportions of 10 g kg−1 (Y1), 20 g kg−1 (Y2), 30 g kg−1 (Y3) and 50 g kg−1 (Y5). Some 540 juvenile E. coioides (initial weight: 10.00 ± 0.05 g) were randomly divided into six groups, each with three replicates and 30 groupers per replicate. The experiment lasted 56 days. Rates of weight gain, special growth, feed coefficient and survival were not significantly influenced by diet. In the foregut and midgut, the villus length in group Y3 and muscle thickness in group Y1 were significantly higher than those in group FM. The expression levels of TLR22, INF-γ, and TNF-α were significantly higher in group Y0 than in Y1, Y2, Y3 and Y5. After V. harveyi challenge, the survival rate was significantly lower in group Y0 than in FM, while dietary supplementation with S. cerevisiae hydrolysate at 10 g kg−1 and 20 g kg−1 (Y1 and Y2) improved survival compared with group Y0 to a level comparable to that of group FM. These results indicate that a low-fishmeal diet supplemented with complex plant proteins and S. cerevisiae hydrolysate provides similar growth performance to a diet with fishmeal as the only protein source. Supplementation with S. cerevisiae hydrolysate increased the villus length and muscle thickness in the foregut and midgut, reduced the expression of intestinal inflammatory factors, and significantly improved resistance to V. harveyi infection.

中文翻译：

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在复杂的植物蛋白中添加酿酒酵母水解物，低鱼粉饮食可改善石斑鱼的肠道形态、免疫功能和哈维弧菌抗病性

摘要 用6种异氮和等脂实验日粮喂养橙斑石斑鱼Epinephelus coioides，评估它们的生长性能、肠道形态、免疫功能和对哈维氏弧菌感染的抵抗力。阳性对照 (FM) 以鱼粉作为唯一的蛋白质来源。阴性对照 (Y0) 饲喂较低比例的鱼粉和植物蛋白。其他组以 10 g kg-1 (Y1)、20 g kg-1 (Y2)、30 g kg-1 (Y3) 和 50 g kg-1 (Y5) 的比例添加了酿酒酵母水解物的 Y0 日粮）。将约540只幼鱼（初始重量：10.00±0.05 g）随机分为6组，每组3个重复，每个重复30条石斑鱼。实验持续了56天。体重增加率，特殊增长，饲料系数和存活率不受日粮的显着影响。在前肠和中肠中，Y3组的绒毛长度和Y1组的肌肉厚度均显着高于FM组。Y0组TLR22、INF-γ和TNF-α的表达水平显着高于Y1、Y2、Y3和Y5组。V. harveyi 攻击后，Y0 组的存活率显着低于 FM，而饮食中添加 10 g kg-1 和 20 g kg-1（Y1 和 Y2）的酿酒酵母水解物与 Y0 组相比提高了存活率达到与 FM 组相当的水平。这些结果表明，添加复合植物蛋白和酿酒酵母水解物的低鱼粉日粮提供与鱼粉作为唯一蛋白质来源的日粮相似的生长性能。补充S。