Dietary Nigella sativa as an Immunomodulator against Infectious Bursal Disease Virus: Gross and Histopathological Evaluation

Abstract

Background: Nigella sativa (black cumin) possesses immunomodulatory and antioxidant properties that may protect lymphoid tissues from damage induced by very-virulent infectious bursal disease virus (vvIBDV) in poultry. This study investigated the gross and histopathological effects of dietary Nigella sativa seed powder (NSSP) supplementation in cockerels experimentally challenged with vvIBDV.

Methods: One hundred day-old Dominant Black Marshal cockerel chicks were randomly allocated into five experimental groups (A–E). Group A received a basal diet and remained unchallenged; group B received a basal diet and was challenged with vvIBDV; group C received NSSP (2.8 g/kg feed) from 21 to 27 days of age (doa) and was unchallenged; group D received NSSP from 21 to 27 doa and was challenged; and group E received NSSP continuously from 1 to 42 doa and was challenged with vvIBDV. Following viral challenge, gross lesions, carcass weight, and histopathological changes in the bursa of Fabricius, spleen, and thymus were evaluated.

Results: No gross or histopathological lesions were observed in groups A and C. Severe lesions were recorded in group B, moderate lesions in group D, and mild lesions in group E. Dietary NSSP supplementation reduced muscle and bursal hemorrhages, splenic congestion, and thymic lymphoid depletion. Although relative bursal and thymic weights were significantly increased in infected birds during the early post-challenge period, lesion severity decreased progressively in NSSP-treated groups, indicating improved lymphoid tissue protection and recovery.

Conclusion: Continuous dietary supplementation with Nigella sativa seed powder effectively mitigated vvIBDV-induced lymphoid damage in cockerels, supporting its potential use as a natural immunomodulatory agent in poultry health management.