The study was designed to evaluate the effects of probiotics (Bacillus subtilis) to enhance immunity, antioxidation, digestive enzymes activity and hematological profile of Shaoxing duck. A population of 200 laying ducks (160 days old) was divided into two groups each further divided in five replications. The control (G₁) were fed on basal diet and (G₂) with B. subtilis 1×10⁸ cfu/kg in addition of basal diet for thirty five days. The results showed that, ducks were treated with probiotics (B. subtilis), their serum IL-2 increased and IL-10 decreased (P<0.05). The concentrations of IgG, IgA and sIgA were observed significantly higher in (G₂) as compared to (G₁). Treatment group (G₂), showed significantly improvement in (SOD), T-AOC and ASAFR activity in serum and liver. However, digestive enzymes amylase and trypsin activity also improved (P<0.05) in (G₂). The blood chemistry analysis showed significant decrease in FT3 and no other significant change observed in hematological profile as compared to (G₁). In conclusion, application of B. subtilis (1×10⁸ cfu/kg) may be beneficial to improve antioxidation response, supportive in innate immunity and digestibility of fowls (Shaoxing duck).

Key words: Bacillus, Enzymes, Homeostasis, Immunity, Immunoglobulin