An experiment was conducted to investigate the modulatory effect of Ginkgo biloba extract(EGB) on immune organ index and the content of immunoglobulins in local humor of digestive tract in broilers.Three hundred and sixty one-day-old healthy Arbor Acres female broilers were divided into five groups,each with six replicates,and fed corn-soybean meal basal diet supplemented with 0,0.15%,0.20%,0.25% EGB or 0.009% aureomycin for 42 days.The results showed that adding 0.20% EGB or 0.25% EGB to diet significantly...