The effect of Bacillus subtilis and B. licheniformis as probiotic bacteria and ferrous Sulfate on some blood parameters of Rainbow Trout (Oncorhynchus mykiss) larvae during incubation period

To investigate the effects of probiotic (BioPlus 2B) (including Bacillus subtilis and B. licheniformis) and iron (Fe(So4)2(7H2O)) supplementation on rainbow larvae blood, a 60 day feeding experiment was conducted. 2700 larvae (average weight 0.135±0.01 gr) were selected and as a treatments aith 3 replications. The application of probiotic and iron suplements were considered as: T1: Probiotic: 1.6×109 CFU(Colony Forming Unit)/g; T2: Probiotic: 1.2×109 CFU/g; T3: Iron: 7mg/kg; T4: Iron: 5mg/kg; T5: Probiotic: 1.6×109 CFU/g with Iron: 7mg/kg; T6: Probiotic: 1.6×109 CFU/g with Iron: 5mg/kg; T7: Probiotic: 1.2×109 CFU/g with Iron: 7mg/kg, T8: Probiotic: 1.2×109 CFU/g with Iron: 5mg/kg; and T9: control treatment (without supplementation with probiotic and iron). At the end of experiment, The highest levels of IgM and WBC were obtained of T1 and T2 (P≤0.05). T8 and T7 showed the highest levels of iron, ferritin and transferrin (P≤0.05). Our findings support that if probiotic just added to feed, IgM levels and WBC of trout larvae would be increased. Whiles administration of both probiotic and iron will be increased iron, ferritin and transferrin levels in blood serum.