The expression of TLRs in BF of chicks treated with HQD were up-regulated, indicating that HQD regulates the anti-infection ability by increasing the mRNA levels of TLR4, -5 and -15, further decreasing the serum LZM and IL-1β, TNF-α, IL-10, IL-6 level of chicks suffered E. coli infection. The gene discussed is TLR4; the disease is escherichia coli infection.