Compatible alternative to antibiotics in broilers: evaluating Nigella sativa as a natural growth promoter

Abstract The restriction or ban of antibiotics as feed additives in poultry production in many countries, including those in the European Union, has prompted the need for safe and effective natural alternatives. This study evaluated the potential of Nigella sativa L. (black cumin) seed extract as a feed additive in broiler chickens, focusing on its effects on performance, carcass traits, blood biochemistry, digestive microbiota, and immune response. A total of 200 one-day-old Ross 308 male chicks were randomly divided into five treatment groups: a control group receiving Virginiamycin (0.2 g/L) and four groups supplemented with 0, 150, 300, or 450 mg/l of N. sativa extract in drinking water from day 1 to 42. Birds receiving 150 mg/l of N. sativa showed significantly higher weight gain, final live weight, carcass yield, and breast and drumstick mass (p < 0.05) compared to other treatments. This group also exhibited lower total cholesterol and LDL levels at day 42, alongside reduced coliform counts and increased Lactobacilli, indicating beneficial effects on gut microbiota. Although feed intake remained unaffected, N. sativa influenced immune parameters: IgG levels decreased at 300 mg/l, while IgM levels increased at 450 mg/l. These results suggest that supplementing broiler diets with 150 mg/l of N. sativa extract may serve as an effective alternative to antibiotics, promoting growth performance, improving metabolic health, and supporting intestinal microbial balance. Further studies are warranted to confirm its efficacy, assess long-term safety, and clarify the mechanisms involved in its growth-promoting and cholesterol-lowering effects.