The purpose of this study was to screening the optimal compound nervilia fordii(Nervilia fordii-A,Herba Houttuyniae-B,Astragalus membranaceus-C) and explore the treatment effects to the pig respiratory disease.The rat models of ALI were induced by intraperitoneal injection of endotoxin.The index of MDA and SOD of pulmonary tissue homogenate were examined to screening the optimal compound Nervilia fordii.The compound nervilia fordii was divided into high,medium and low dosage added into daily ration of weani...