Effects of dietary corn-fermented protein as a sustainable ingredient on growth performance, immune response, and disease resilience in whiteleg shrimp (Litopenaeus vannamei)

Abstract

This study involved a 56-day feeding trial to investigate how corn-fermented protein (CFP) as a fishmeal alternative influences the performance of whiteleg shrimp (Litopenaeus vannamei). Four dietary treatments were tested: a control and three experimental diets containing 4% (CFP4), 8% (CFP8), and 12% (CFP12) CFP. Growth performance, immune response, histological integrity, muscle quality, pigmentation, and disease resistance were assessed under controlled aquaculture conditions. Shrimp fed CFP8 and CFP12 exhibited growth performance comparable to the control, with improved protein retention and slightly enhanced feed conversion ratios. Flesh color analysis revealed significantly elevated b* (yellow-blue component) values in CFP8 and CFP12 groups, indicating increased yellow pigmentation, while L* (lightness) and a* (red-green component) values remained unchanged. Muscle texture was unaffected by CFP inclusion, indicating no deterioration in meat quality. Histological examination showed stable intestinal morphology, with a reduction in hepatopancreatic R-cells at higher CFP levels, suggesting altered metabolic activity. Immunologically, CFP supplementation enhanced phagocytic activity (CFP12) and total hemocyte count (CFP4/CFP8), although some immune gene expressions were downregulated. Post-challenge with pirA + /pirB + Vibrio parahaemolyticus, shrimp fed CFP diets, particularly CFP12, demonstrated improved survival and disease resilience. These findings support the use of CFP as a sustainable, health-promoting alternative to fish meal in shrimp aquafeeds, with beneficial effects on immunity, pigmentation, and pathogen resistance.