Studies on Bacillus subtilis, as Potential Probiotics, on the Hematological and Biochemical Parameters of Rainbow trout, Oncorhynchus mykiss (Walbaum)

The probiotic activity of Bacillus subtilis was evaluated by its effect on the hematological and biochemical factors of rainbow trout. The experience was carried out in 2 groups (Control and Treatment) and 3 replicates. In Control group, probiotic was not applied in diet but in Treatment group, B. subtilis was administered in feed at a concentration of 10 cells/g. In the day of thirty, 5 blood samples were caught from every replicate for biochemical and hematological experiments. Results showed that B. subtilis addition to diet had not effect on erythrocyte count, hemoglobin, hematocrit, mean cell volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) and there was no significant difference among two groups (p>0.05). But the leucocyte count, percent of lymphocyte, serum total protein, serum albumin, IgM and lysozyme of T group was significantly higher than that of C group (p<0.05), whereas percent of neutrophile and monocyte of C group was significantly higher than that of T group (p<0.05). The results suggest that B. subtilis can stimulate immune parameters in rainbow trout.