Response of gut microbiota, antioxidation, and disease resistance to pacific shrimp fed distiller's dried grains with solubles replaced soybean meal

Abstract

This experiment aimed to examine the potential of distillers dried grains soluble (DDGS) meal as a substitute for soybean meal (SBM) in the Pacific shrimp diet. The study aimed to investigate how DDGS affected disease resistance, antoxidation, and gut microbiota. 840 shrimp were given varied diets with varying concentrations of DDGS. D1 (0%), D2 2%, D3 4%, D4 6%, D5 8%, D6 10%, and D7 12% were the DDGS levels. Each group had three replicates of the 56-day experiment. Initially, the weight was 0.19 ± 0.00 g. The survival rate was consistently 100% for shrimp-fed DDGS, except for group 7 (14%) and the control group, where shrimp mortality was observed. The total protein (TP) content was improved as the inclusion level of DDGS increased. The glucose (GLU) exhibited a downward trend with higher DDGS inclusion. Similarly, the TG and CHO levels in the serum decreased as the DDGS levels increased. The activities of ALT (alanine transaminase) and AST (aspartate aminotransferase) decreased as the dietary DDGS increased, with the control group showing significantly higher ALT and AST activities than those fed DDGS diets (P < 0.05). Furthermore, the SOD (superoxide dismutase) activity significantly increased with higher DDGS levels, while the MDA (malondialdehyde) activity showed the opposite trend. Notably, the control exhibited the highest MDA activity value. The most prevalent phylu found in the gut microbiota were Proteobacteria, and Bacteroidetes. Upon completion of a 7-day bacteria challenge, it was observed that shrimp fed with the control diet had a lower mortality rate compared to those fed the DDGS diet. Based on the parameters measured in this study, it was determined that replacing 10% of SBM with DDGS in the feed of Pacific shrimp is feasible.