Synergistic bentonite and Trichosporon mycotoxinivorans detoxifier restores humoral immunity to avian influenza vaccination and prevents histopathological lesions in mycotoxin-exposed broiler

Background and Aim: Mycotoxin contamination in poultry feed, particularly aflatoxin B1 (AFB1) and ochratoxin-A (OTA), induces immunosuppression and compromises vaccine efficacy, leading to substantial economic losses in broiler production. Avian influenza (AI) remains endemic in several poultry-producing regions, where vaccination is the primary control strategy. However, impaired immune responses due to mycotoxin exposure frequently result in vaccination failure. This study aimed to evaluate the efficacy of a combined mycotoxin-detoxifier containing bentonite and Trichosporon mycotoxinivorans in restoring humoral immune responses to AI vaccination and mitigating histopathological lesions in broilers exposed to AFB1 and OTA. Materials and Methods: A total of 40 broiler chickens were randomly assigned to four groups: negative control (C−), positive control (C+), treatment 1 (T1; 1.1 g/kg detoxifier), and treatment 2 (T2; 1.6 g/kg detoxifier). Groups C+, T1, and T2 received feed contaminated with AFB1 and OTA (0.1 mg/kg each). Birds were vaccinated against AI at 7 days with a booster at 21 days. Antibody titers were measured by hemagglutination inhibition at 14, 21, 28, and 35 days. Histopathological evaluations of the proventriculus and bursa of Fabricius were conducted on day 35. Parametric and non-parametric statistical analyses were applied with significance set at p < 0.05. Results: Antibody titers were significantly reduced in the mycotoxin-exposed group (C+) compared to the negative control (C−) at all post-vaccination time points. Supplementation with the detoxifier significantly improved antibody titers, particularly in T2, with values comparable to those of the negative control. Histopathological analysis revealed severe inflammatory cell infiltration, oxyntico-peptic cell necrosis, and degeneration in C+, whereas T1 and T2 groups demonstrated significant amelioration of lesions, with T2 showing the greatest protective effect. Similarly, lymphoid follicle depletion and necrosis in the bursa of Fabricius were markedly reduced in detoxifier-treated groups. Conclusion: Dietary supplementation with a mycotoxin-detoxifier, particularly at 1.6 g/kg, effectively mitigates the immunosuppressive effects of AFB1 and OTA, enhances humoral responses to AI vaccination, and reduces histopathological damage in broilers. This strategy represents a practical and effective approach to improving poultry health and vaccine performance under mycotoxin-contaminated conditions. Keywords: aflatoxin B1, avian influenza, bentonite, broiler chickens, humoral immunity, mycotoxin-detoxifier, ochratoxin-A, Trichosporon mycotoxinivorans.