Results
Growth performance and feed utilisation
The effects of the dietary supplementation of KDF on the growth performance and feed utilisation of O. niloticus are summarised in Table 2. At the end of the feeding trial, the fish groups fed on (0.2% and 0.3% KDF) showed a significant (p < 0.05) increase in the live body weight gain by (14.9% and 15.8%), respectively, and SGR by (11.6% and 12.9%), compared to the control group. In contrast, the group fed on (0.1% KDF) showed a numerical increase in the live body weight gain by (5%) versus the control group. The results of the feed utilisation in terms of FCR and PER of the fish groups supplemented with (0.2% and 0.3% KDF) showed a significant improvement in the FCR of (9.3% and 9.1%), respectively, whereas the fish group supplemented with (0.1% KDF) showed a non-significant improvement in the FCR of (3.7%). The PER was significantly (p < 0.05) increased in fish fed diets supplemented with (0.2% and 0.3% KDF) compared to those a fed diet supplemented with (0.1%KDF) and the control diet.