Prophylactic and immune modulatory influences of Nigella sativa Linn. in broilers exposed to biological challenge

Background and Aim: Prophylaxis and disease prevention is an essential strategy among biorisk management in poultry farms that stimulate and maintain the birds' immunity. The aim of this study was to investigate the prophylactic, and immune-stimulant influence of Nigella sativa Linn. in broilers under biological stress. Materials and Methods: A total of 250 1-day-old (ross) chicks were divided into 5 groups; four of which were supplemented with 1.4%, 2.8%, 4.2%, and 5.6% N. sativa Linn., respectively. The four supplemented groups were challenged with Escherichia coli O-157:H-7 1.5x10(8) at a 14th day old. A total of 1050 samples (150 serum, 150 swab, and 750 organ samples) were collected and examined. Results: A highly significant increase (p < 0.01) in 5.6% N. sativa Linn. supplemented group in performance traits (body weight, weight gain, and performance index), biochemical parameters (proteinogram, liver enzymes, and creatinine), immunoglobulins concentration, and immune organs' weight. Meanwile, liver showed improvement of histoarchitecture without fibrosis. Heart showed a mild pericarditis with a mild degree of hydropic degeneration. Bursa, thymus, and spleen showed lymphoid hyperplasia. Conclusion: A concentration of 5.6% N. sativa Linn. in broiler's feed can improve the immune response and subsequent resistance of broilers against diseases.