<scp>POET CFP</scp>, a corn‐fermented protein concentrate, as a potential novel aquafeed ingredient for juvenile European sea bass, <i>Dicentrarchus labrax</i>

Abstract This study evaluated POET CFP, a corn‐fermented protein derived from dry‐mill bioethanol production, as a potential candidate for use in European seabass aquafeeds. The apparent digestibility coefficients (ADC) of POET CFP were evaluated and compared to soybean meal. The ADC of POET CFP protein was higher than that of soybean meal (92.7% vs. 83.9%), and the neutral detergent fiber (NDF) of POET CFP was partially digested (26%), while that of soybean meal was completely undigestible. However, the ADC of energy was similar between the two feedstuffs (70%). Two growth trials were performed to evaluate the effect on growth performance and feed utilization of European seabass for total or partial replacement of corn gluten meal (CGM) (Trial 1) or CGM and soybean meal (CGM + SBM) (trial 2) with POET CFP. For that purpose, a practical diet with 48% protein and 18% lipids was formulated to include 20% fish meal, 15% CGM, and 15% SBM (control diet). For trial 1, four diets similar to the control were formulated with POET CFP replacing CGM at 25%, 50%, 75%, and 100%. For trial 2, three other diets similar to the control were formulated, but POET CFP replaced CGM + SBM at 33%, 66%, and 100%. Triplicate groups of European seabass juveniles with 26 g were fed these diets for 85 days. Results of Trial 1 showed that total dietary replacement of CGM with CFP did not affect growth performance, feed intake, feed utilization, and whole‐body composition. N retention (% N intake) was also unaffected, but energy retention (% energy intake) linearly increased with dietary CFP inclusion. Further, the histomorphological appearance of the posterior intestine was unaffected by dietary CFP inclusion. Results of trial 2 showed that total dietary replacement of CGM + SBM with CFP did not affect growth performance, feed intake, feed utilization, and N and energy retention (% intake). However, polynomial contrasts showed a significant linear trend for increased growth performance and feed efficiency with the dietary inclusion of CFP. Whole‐body dry matter and lipid content linearly decreased with the dietary increase of CFP. No differences were observed between groups in the histomorphological appearance of the distal intestine. This study showed that CFP could completely replace CGM and SBM in diets for European seabass juveniles without affecting growth performance and feed utilization or adversely affecting posterior intestine morphology.