Probiotic Potential of Dietary Bacillus amyloliquefaciens in Enhancing Health Parameters of Amur Common Carp (Cyprinus carpio haematopterus)

The use of probiotics in aquaculture has gained increasing attention as a sustainable strategy to enhance fish health and immunity. This study investigates the effects of dietary supplementation with Bacillus amyloliquefaciens on the haematological and immune parameters of Amur common carp (Cyprinus carpio haematopterus). A feeding trial was conducted in which fish were divided into four groups and fed diets containing 0% (control- T0), 0.5% (T1), 1% (T2) and 1.5% (T3) Bacillus amyloliquefaciens (108 CFU g-1) supplementation for a period of 90 days. - The haematological parameters viz: RBC, WBC, haemoglobin, platelets, haematocrit, MCV, MCH, and MCHC were showed significantly higher values (P< 0.05) in the T1 group compared to all other treatment groups and the control. Additionally, the T1 group exhibited the highest levels of total serum protein, albumin, globulin, and albumin/globulin ratio, with statistically significant differences (P< 0.05). Significant enhancement (P< 0.05) of immune parameters was also observed in Amur common carp fed with the T1 diet, which, included the Nitroblue Tetrazolium assay, lysozyme activity, phagocytic activity, and total myeloperoxidase activity. The 0.5% probiotic inclusion (T1) yielded the most pronounced enhancements in haematological and immune parameters, indicating that this concentration may be optimal for improving fish health. The findings suggest that Bacillus amyloliquefaciens can serve as a beneficial probiotic in aquaculture, enhancing disease resistance and overall physiological well-being in Amur common carp. These results contribute to the growing body of evidence supporting probiotic use as a natural alternative to conventional disease management strategies promoting sustainable aquaculture practices.