Abstract
Research on finding alternative protein sources to replace fishmeal (FM) has become a central issue in the nutrition field. Extensive research has been carried out on the replacement of FM with soybean meal (SBM); however, little is known about the replacement of FM with enzyme-treated SBM (ESBM). In this study, five isolipidic and isonitrogenous diets were formulated by substituting FM with ESBM at the levels of 0% (FM, control diet), 5% (ESBM25), 10% (ESBM50), and 15% (ESBM75) which were fed to juvenile shrimp for 8 weeks. And we found that replacing FM with ESBM at 5%-10% levels in shrimp diets had no impact on shrimp growth performance and feed utilization. However, substituting 10% ESBM for FM in the shrimp diets promoted the expression of growth-related genes and maintained consistent intestinal microbiota compared to the control group. Replacing FM with 15% ESBM in the shrimp diets inhibited shrimp growth, suppressed mTOR gene expression, and promoted the proliferation of harmful intestinal bacteria. Furthermore, replacing FM with different ESBM did not affect the intestinal health of shrimp. Taken together, our research provides that replacing FM with 10% ESBM is feasible. These findings not only enrich our knowledge of FM proteinogen replacement but also provide a reference for the use of ESBM as a substitute for FM in commercial feeds for shrimp Penaeus vannamei as well as other shrimp species.