Apparent protein digestibility
The APD was improved for tilapia fed on diets supplemented by (0.1%, 0.2% and 0.3% KDF) compared to the fish group fed on the control diet. A better digestibility was obtained with the group supplemented with (0.2% and 0.3% KDF), as shown in Table 2.
Biochemical serum analysis
The data in Table 3 show that a non-significant difference was found among all experimental groups, including the control group, for both the ALT and AST activity. The data for urea, creatinine and BUN showed a slight, non-significant reduction.