Soybean meal is one of the major components of aquatic animal diets, whereas little information is available about the evaluation of soybean meal growth suppression mode of action. A 42-day feeding trial was performed to assess the effects of dietary soybean meal on growth performance, apparent digestibility, intestinal digestive enzyme activity, and muscle growth–related gene expression of Litopenaeus vannamei. A total of 600 shrimp were randomly distributed into 20 tanks with 30 shrimp per tank and four tanks per group. The soybean meal was added to the diets at the rate of 20% (T20), 28% (T28), 35% (T35), 42% (T42), and 50% (T50), respectively. Shrimp were fed with apparent satiation three times daily. Results indicated that the final body weight, weight gain rate, specific growth rate, feed intake, intestinesomatic index, dressed weight percentage, and the apparent digestibility coefficients of dry matter, crude protein, crude lipid, and ash were linearly decreased (p < 0.05), but feed coefficient was linearly increased (p < 0.05) as dietary soybean meal increased from 20% to 50%. The intestinal trypsin and amylase activities were decreased (p < 0.05) as dietary soybean meal increased from 20% to 50%, and reached significance at the level of 35%, 42%, and 50%. Shrimp fed with T20 had higher (p < 0.05) intestinal lipase activity than those fed with other diets. The mRNA relative expression of growth hormone, myogenic regulatory factor 5, and target of rapamycin was downregulated (p < 0.05) as dietary soybean meal increased from 20% to 50%. To conclude, dietary soybean meal exceeded 28% significantly inhibited growth performance of L. vannamei, mainly due to the negative impact of soybean meal on digestion and feed utilization and also the inhibition on the muscle growth and related gene expressions.

豆粕是水产动物饲料的主要成分之一，而关于豆粕生长抑制作用模式的评价信息很少。进行了为期 42 天的喂养试验，以评估日粮豆粕对生长性能、表观消化率、肠道消化酶活性和肌肉生长相关基因表达的影响。南美白对虾. 总共600只虾被随机分配到20个缸中，每缸30只虾，每组4缸。豆粕添加到日粮中的比例分别为 20% (T20)、28% (T28)、35% (T35)、42% (T42) 和 50% (T50)。每天3次以明显饱腹感喂虾。结果表明，最终体重、增重率、比生长率、采食量、肠体指数、屠宰率以及干物质、粗蛋白、粗脂和灰分的表观消化系数呈线性下降。p< 0.05），但进料系数呈线性增加（p< 0.05)，因为日粮豆粕从 20% 增加到 50%。肠道胰蛋白酶和淀粉酶活性降低（p< 0.05) 随着日粮豆粕的比例从 20% 增加到 50%，并在 35%、42% 和 50% 的水平上达到显着性水平。用 T20 喂养的虾具有较高的 (p< 0.05) 肠道脂肪酶活性高于用其他饮食喂养的那些。生长激素、生肌调节因子5和雷帕霉素靶点的mRNA相对表达下调（p< 0.05)，因为日粮豆粕从 20% 增加到 50%。综上所述，日粮豆粕超过 28% 显着抑制了南美白对虾，主要是由于豆粕对消化和饲料利用的负面影响以及对肌肉生长和相关基因表达的抑制。