Fish fed on diets supplemented with A. pinnata and B. subtilis showed improved responses compared to the control, with the T3 diet (A. pinnata 1.5 g kg-1 + B. subtilis 1×106 CFU mL-1) showing significantly better growth in terms of higher % weight gain (87.20%), improved FCR (2.12), and survival rate (p < 0.05). Additionally, digestive enzyme such as protease (82.35 ± 1.95 U/mg), lipase (3.79 ± 0.06 U/mg), amylase (0.313 ± 0.007 U/mg), cellulase (0.131 ± 0.02 U/mg) activities were significantly higher than the control, indicating enhanced digestion of proteins, lipids, carbohydrates, and fibre. Serum biochemical indices significantly improved across all supplemented treatments, with T3 exhibiting the most pronounced response-reduced liver enzyme (SGOT, SGPT, ALP), glucose, urea, creatinine levels, and increased total protein indicating better metabolic health of C. carpio. The combined dietary supplementation of A. pinnata and B. subtilis significantly improved growth and health in C. carpio with T3 diet being most effective; this combination offers sustainable approach to enhance productivity and fish health in carp aquaculture.
Figure 1: Treatment-dependent alterations in (A) growth performance and (B) intestinal digestive enzyme activities of C. carpio fingerlings fed diets supplemented with A. pinnata and varying concentrations of B. subtilis.