Effects of Dangguibuxue Tang, a Chinese herbal medicine, on growth performance and immune responses in broiler chicks.

The effects of Dangguibuxue Tang (DBT) on growth performance and immunity response in immunosuppressed broiler chicks were investigated in this study. 240 one-d-old broiler chicks (DaHeng S01) were randomly divided into 4 groups, 2.0% DBT-treatment (A), 0.5% DBT-treatment (B), cyclophosphamide-control (C), and control group (D). From 4 d to 7 d of age, chicks in group A, B and C were given cyclophosphamide (CY) at a dosage of 100mg/kg body weight (BW) daily by intraperitoneal injection to induce immunosuppression. Chicks in group D were given an equal volume of physiological saline daily by intraperitoneal injection and considered normal chicks. Groups A and B were supplemented with 2.0% or 0.5% of DBT in the drinking water from 8 d to 42 d of age. Groups C and D did not receive any additional medication. The results revealed that chicks from group B had lower feed:gain rate (FGR), lower total mortality, higher immunity organ indexes, higher levels of Newcastle disease (ND) antibody and infectious bursal disease (IBD) antibody, higher interleukin-2 and interleukin-6 levels, and greater lymphocyte proliferative responses to concanavalin A (ConA) during the experiment than those from group C. However, no significant difference in the immunity status in the two levels of DBT-treatment was observed. These results indicate that supplementation of 0.5% of DBT can improve both cellular immunity and humoral immunity in immunosuppressed broiler chicks.