The use of plant-based fermentation products as substitutes for costly feed ingredients like fishmeal and soybean meal has been at the forefront of aquaculture research. This study investigated the effects of dietary fermented mulberry leaf powder (FMLP) on grass carp (0.86 ± 0.07 kg). Fish were fed a basal diet supplemented with 0%, 5%, 10%, or 15% FMLP for 70 days to assess impacts on growth, muscle quality, antioxidant stat...