Evaluation of Ethanol Coproducts as Sustainable Protein Sources in Pacific White Shrimp (Litopenaeus vannamei) Diets

Abstract

Use of corn-fermented protein (CFP), a new product produced using Fluid Quip Technologies, as a protein source in aquaculture feeds, constitutes a promising option due to its dependable supply and cost-effectiveness. In this study, two growth trials were performed to evaluate the effectiveness of CFP products such as CFPA (48% crude protein [CP]), CFPB1 (50% CP), and CFPB2 (60% CP) from two different sources (A and B) in practical diets for juvenile Pacific white shrimp (Litopenaeus vannamei). The test diets in both trials were formulated to be isonitrogenous and isolipidic (36% crude protein and 6% crude lipid). These diets were produced by supplementing the basal diet with 5%, 10%, 15%, and 20% CFPA or 4%, 8%, 12%, and 16% of CFPB1 and CFPB2 to replace soybean meal (SBM) on an isonitrogenous basis. In a 6-week experiment, shrimp (1.02 ± 0.02 g mean weight, 15 shrimp per tank, n = 6) were offered CFPA diets. Growth parameters and protein retention showed no significant differences among diets. However, a significant feed conversion ratio (FCR) increase was observed when shrimp were fed a diet containing 20% CFPA compared to the basal and 5% CFPA diets. Physiological gene expression analysis revealed no signs of gut inflammation or shifts in hepatopancreas digestive enzymes (p  > 0.05). However, the expression of immune-related tnf-α gene was significantly upregulated (p  < 0.05) in shrimp-fed CFPA 25% diet compared to CFPA 5% and control groups. In a 7-week experiment, shrimp (0.55 ± 0.01 g, 15 shrimp per tank, n = 5) received experimental CFPB1 or CFPB2 diets. No differences were observed in growth performance. This research highlights the potential of CFP as a protein source in shrimp diets by expanding the range of feed ingredients and identifying optimal inclusion levels.