Effects of Dietary Curcumin Supplementation Under High-Level Fishmeal Replacement with Clostridium autoethanogenum Protein in Penaeus vannamei: Growth Performance, Immunity, Intestinal Health, and Transcriptome Responses

Abstract

Simple Summary Fishmeal is an important but costly and limited protein ingredient in shrimp feed. Clostridium autoethanogenum protein is a promising alternative, yet high-level inclusion levels may adversely affect shrimp growth and health. This study evaluated whether dietary curcumin supplementation in Penaeus vannamei fed a diet in which 50% of the fishmeal was replaced with CAP. Three experimental groups were designed in this study: a fishmeal control, a high-CAP diet, and the same high-CAP diet supplemented with curcumin. After eight weeks, shrimp fed the high-CAP diet showed reduced growth, adverse histological changes in the intestine and hepatopancreas, lower nonspecific immune enzyme activities, and alterations in intestinal microbial community composition. Compared with the high-CAP group, curcumin supplementation was associated with improvements in growth performance, tissue morphology, immune enzyme activities, and intestinal microbial profiles. Transcriptomic analysis suggested that identified changes were associated with metabolic and immune-related biological processes. Because a fishmeal-based diet supplemented with curcumin was not included, these findings should be interpreted specifically under high-CAP dietary conditions. Overall, the results support the potential application of curcumin as a functional feed additive in CAP-based, low-fishmeal diets for shrimp.