Challenge test
The mean cumulative mortality of the experimental fish groups 15 days post challenge with A. hydrophila is illustrated in Fig. 2. Tilapia fed on the control diet showed the highest mortality rate (40%) compared with the potassium-diformate-supplemented groups, which showed a reduction in the mortality rate from 13% in the groups treated with 0.1% and 0.2% to 7% in the group fed on 0.3% KDF.