Pre-Administration with Nigella sativa Seed Powder Caused Alterations in Antibody and Serum Interferon Gamma Profiles in Cockerels Challenged with a Very Virulent Infectious Bursal Disease Virus

Infectious bursal disease (IBD) compromises the immune system of young birds, lowering protective antibody levels.This study assessed antibody and serum interferongamma (INF-γ) responses in cockerels pre-treated with Nigella sativa seed powder (NSSP) and challenged with very virulent IBD virus (vvIBDV).One hundred one-dayold Dominant Black Marshal Cockerels were assigned to five groups (A-E, 20 birds each).Groups A and B received standard feed from 1-42 days of age; groups C and D received NSSP from 21-27 days of age; group E received NSSP continuously from 1-42 days of age.All birds were vaccinated against Newcastle disease.On day 28, groups B, D, and E were orally challenged with vvIBDV.Blood samples were analyzed for IBD antibody and INF-γ.Maternal antibody titres declined below protective levels by 14 days in groups A-D but remained protective in group E. Post-challenge, groups D and E showed significantly higher antibody titres, with group E maintaining the highest levels.Serum INF-γ increased from 7 to 21 days of age in all groups, and from 29 to 42 days of age, group E exhibited the highest levels compared to D and B. Pre-administration of NSSP slowed maternal antibody decay and enhanced post-challenge immune responses.Dietary inclusion of NSSP may therefore provide a natural strategy to sustain IBD antibody protection and improve immune performance in poultry.