Ali A. Abid Al-Hisnawi, Doaa Ali Beiwi
The current study was conducted to investigate the influence of Bacillus subtilis feed additive on hematological parameters, blood serum parameters and the levels of cytokines, including Transforming growth factor beta (TGF-β) and Interleukin 1 beta (IL-1β), of common carp. The probiotic was isolated from local soils using PCR approach for amplification of 16S rDNA and added to the diet in a dose of ~107 CFU g−1. The feeding trial was carried out for six weeks. A total of 64 fish (77.2 ± 0.86 g) were randomly divided into two groups: control group (basal diet) and experimental group. Compared to the control group, the carp fed probiotic supplemented diet displayed a significant elevation in mean cell haemoglobin concentration (P <0.05). The other haematology parameters were not significantly affected. The blood serum profiles i.e., blood urea, cholesterol and random blood sugar, were not affected by the experimental diet. However, the group of fish fed probiotic supplemented diet revealed high significant in serum creatinine compared to the control group. The experimental carp displayed significant improvements in IL-1β level compared to the control group (P=0.004). On the other hand, the level of TGF-β was lower in the probiotic treated fish but no significant differences were observed (P=0.05). The results of the present study, display a possible role for B. subtilis for improving the health status of common carp.