Attention is rising to valorizing plant by-products as ingredients for aquafeeds, complying with the circular bioeconomy approach. In this context, two trials were performed to test the potential of POET CFP , a corn-fermented protein derived from dry-mill bioethanol production, to replace corn gluten meal (CGM; trial 1) or CGM plus soybean meal (SBM; trial 2) in practical diets for European seabass .
A control diet was formulated similar to practical diets (48% protein and 18% lipids ), including 20% fish meal and 15% CGM and SBM . For the first trial, f our other diets were formulated similar to the control but with POET CFP replacing CGM at 25%, 50%, 75%, and 100%. For the second trial, three other diets were formulated similar to the control but with POET CFP replacing CGM and SBM at 33%, 66, and 100%. The trials were performed simultaneously, with t riplicate groups of European sea bass with an initial body weight of 26 g fed these diets for 85 days.
In the first trial, dietary replac ement of corn gluten meal for POET CFP did not affect the fish’s growth performance, feed intake, feed utilization, or whole body composition. In the second trial, no significant differences in final body weight, weight gain, feed intake, and feed efficiency were also observed. However, polynomial contrasts showed a significative linear trend for these parameters to increase with the dietary inclusion of POET CFP. Whole-body dry matter and lipid content linearly decreased with the dietary increase of POET CFP. In both trials, the h istological morphology of the posterior intestine was un affected by dietary POET CFP inclusion.
Overall, the results of this study indicate that POET CFP can completely replace corn gluten meal and soybean meal in diets for European sea bass without affecting the growth performance and feed utilization of European seabass juveniles.