The activation of TLRs also mediated the activation of IFN regulatory factor 3/7, primarily by recruiting MyD88 or TNF receptor-associated factor 6, which ultimately activated I and II IFNs (i.e., IFN-α, IFN-β, and IFN-γ). In the lungs of tested chickens, both ZH283 and SW8 induced significantly upregulated expression levels of IFN-α, IFN-β, and IFN-γ by 7.55- and 75.97-fold, 68.23- and 362.80-fold, 30.11- and 85.31-fold, respectively (p < 0.05) compared to uninoculated chickens (Figures 4G–I). In contrast to the lung, the brain, spleen, and bursa of Fabricius showed different expression patterns in the levels of IFN-α, IFN-β, and IFN-γ in response to ZH283 and SW8 infection. However, ZH283 induced the expression levels of IFN-α, IFN-β, and IFN-γ to a greater extent than SW8 in the tested tissues of infected chickens.