Nigella sativa as an antibiotic alternative to promote growth and enhance health of broilers challenged with Eimeria maxima and Clostridium perfringens

The poultry industry has significant coc-cidiosis and necrotic enteritis (NE) challenges, leading to high mortality and unacceptable growth without antibiotic treatment. This research explored supple-menting Nigella sativa (black cumin) seed oil in poultry feed to mitigate coccidiosis and prevent or lessen NE in broilers. In vivo studies consisted of 384 and 320 Cobb 500 male broiler chicks distributed in a randomized com-plete block experimental design for trials 1 and 2, respec-tively. The first trial compared 3 concentrations (1, 2, and 5 mL/kg) of black cumin seed oil (BCSO), and trial 2 compared 2 concentrations (2 and 5 mL/kg) BCSO, with birds challenged with Eimeria maxima and Clos-tridium perfringens (Cp) strains Cp#6 and Cp#4, respectively. Broiler live performance, NE disease out-comes, and Cp populations were measured for both tri -als. A commercially available BCSO oil product, determined in a preliminary in vitro study to have the highest anti-Cp activity, was selected for in vivo studies. Gas chromatography-mass spectrometry analysis indi-cated the major bioactive compounds p-cymene, thymo-quinone, carvacrol, and thymol were present in the BCSO. In trial 1 with strain Cp#6, BCSO concentra-tions of 2 and 5 mL/kg reduced NE lesion score and mor-tality rate to 1.6% compared with 7.8% for positive control, with no adverse impact on live performance. In trial 2 with strain Cp#4, BCSO reduced NE lesion scores and mortality rate to 35.9% compared with 51.6% for positive control and also improved weight gain when there was a Cp infection in broiler chickens. The current study compared NE in broilers challenged with 2 differ-ent Cp strains producing different levels of NE. Follow-ing Cp infection, both the population of vegetative cells and spores of Cp in cecal contents decreased for all treat-ments in trial 2. In conclusion, BCSO at concentrations of 2 and 5 mL/kg enhanced broiler live performance and alleviated NE and has potential as a natural, non-medi-cation antimicrobial nutritional supplement for use as a feed additive in chickens.