Immunomodulatory Potential of Moringa oleifera Seed Extract on Immune Responses in Broiler Chickens Following Vaccination against Infectious Bursal Disease Virus

Infectious bursal disease virus (IBDV) continues to pose a serious challenge to broiler production because of its immunosuppressive effects, while maternally derived antibodies (MDA) and antigenic variation can reduce vaccine efficacy. Plant-derived immunomodulators may improve vaccine response, but their role in IBDV immunity is still not well defined. This study aimed at investigating the immunomodulatory potential of Moringa oleifera seed extracts in broiler chickens immunised with a live intermediate-plus IBDV vaccine (Bursa B2K). Five groups were used: group A received 400 mg L⁻¹ methanolic extract, group B 200 mg L⁻¹ methanolic extract, group C 400 mg L⁻¹ aqueous extract, group D 200 mg L⁻¹ aqueous extract, and group E served as the control. Birds were vaccinated on day 14, and blood samples were collected 4 times at 2 weeks interval for ELISA antibody titration. Histological evaluation of the intestine and bursa of Fabricius was also conducted. Group A maintained significantly higher titres than the control, suggesting that the methanolic extract at 400 mg L⁻¹ enhanced persistence of the humoral response. Aqueous extracts showed weaker effects, indicating the importance of solvent and dose. Histology further showed increased lymphocyte density in the intestine and bursa in group A, suggesting enhanced gut-associated and primary lymphoid responses. These findings indicate that methanolic M. oleifera seed extract may serve as a useful immunomodulatory adjunct for improving IBD vaccination in broilers.