IFNG and infection: With respect to the supplemented groups, a significant downregulation was recorded in IFN-γ mRNA expression in chickens of S-UROEE, S-CsNPs and S-UROEE-CsNPs groups after primary and secondary infection in relative to NC group; the expression was downregulated (P < 0.05) by ~ 0.82, 0.55, 0.64-fold at 6 DPPI as well as by ~ 0.45, 0.47 and 0.55-fold at 0 DPSI and by ~ 0.60, 0.63 and 0.64-fold at 6 DPSI in S-UROEE, S-CsNPs and S-UROEE-CsNPs groups, respectively (Fig. 24).