Chicken colibacillosis-the most common disease of poultry, is caused mainly by avian pathogenic Escherichia coli (APEC). It has a major impact on the poultry industry worldwide. The present study was conducted to investigate the therapeutic effects of Xiaochaihu Decoction (XCHD) supplementation on clinical manifestation, organ index, bacterial load in organ and inflammatory mediators in a chicken model challenged with APEC. The results showed that all doses of XCHD significantly elevated the survival rate of infected chickens. XCHD improved the clinical signs of infected chickens, reduced the organ index, reduced the bacterial load of organs, and inhibited the secretion of serum and pulmonary inflammatory factors IL-1β, IL-6 and TNF- α. Taken together, this study demonstrates that XCHD had protective effects on APEC-infected chickens. Its mechanism includes anti-inflammatory and antibacterial effects. These findings may contribute to the further study of the mechanism of the formula and the prevention or treatment of colibacillosis in poultry. The significance of this study is that it provides a certain theoretical basis for the replacement of antibiotics by XCHD.
Keywords: Xiaochaihu Decoction; avian pathogenic Escherichia coli; chicken colibacillosis; therapeutic effect; traditional Chinese veterinary medicine.