The potential of Clostridium autoethanogenum, a new single cell protein, in substituting fish meal in the diet of largemouth bass (Micropterus salmoides): Growth, feed utilization and intestinal histology

Abstract This study investigated the effects of replacing fishmeal with Clostridium autoethanogenum protein (CAP) on growth, feed utilization and intestinal histology of largemouth bass (Micropterus salmoides). The control diet contained 350 g/kg fishmeal, and then dietary fishmeal was decreased to 300 g/kg, 250 g/kg, 200 g/kg, 150 g/kg and 100 g/kg by CAP inclusion, respectively (FM-30, FM-25, FM-20, FM-15, FM-10). The largemouth bass (110.0 ± 1.0 g) were fed one of the six diets for 8 weeks. The groups of FM-30, FM-25 and FM-20 showed the similar weight gain (WG) and feed conversion ratio (FCR) to the control (P > 0.05), while the WG of FM-10 group was decreased by 15.9%, and FCR increased by 0.12 when compared to the control (P   0.05). In conclusion, CAP could replace 150 g/kg fishmeal in diet (350 g/kg fishmeal) without adverse effects on growth, feed utilization and intestinal histology of largemouth bass.