Feasibility of replacing antibiotic feed promoters with the Chinese traditional herbal medicine Bazhen in weaned piglets

This study investigated the feasibility of replacing antibiotic as growth promoter for weaned piglets with the Chinese traditional herbal medicine Bazhen. Thirty-six weaned piglets (average initial body weight 8.92 +/- 1.18 kg) were used in this study. Pigs were blocked according to weight, sex and litter origin, and then randomly assigned to control (basal diet), antibiotics (100 ppm chlortetracycline and 100 ppm oxytetracycline) and Bazhen (1%) groups, with three pens per group. Piglets had free access to water and feed during this 8-week study period. Experimental results indicated that average daily gain of the Bazhen group was higher than that of the control group, but lower than that of the antibiotics group. However, feed intake was reduced while feed to gain ratio was improved in the Bazhen group compared to the control and antibiotics groups. The Bazhen group showed higher neutrophil activity and IgG levels than the control group. The increase in white blood cell counts of the Bazhen group when challenged with Escherichia coli lipopolysaccharide was higher than that in the control and antibiotics groups. Moreover, IL-6 and TNF-alpha (tumor necrosis factor-alpha) levels were higher in the Bazhen group than in the antibiotics group. Red blood cells and gamma-globulin levels were higher in the Bazhen group than in the antibiotics group and in the control group, respectively. On the other hand, the antibiotics group displayed the highest amount of SRBC (sheep red blood cell) antibody titers, and differed significantly from the control group. Some immune responses such as white and red blood cells, IL-6 and TNF-alpha levels were greater at weaning in the piglets of the Bazhen supplemented group than in those of the antibiotics group. Thus, Bazhen could be a potential substitute for antibiotics (chlorotetracycline and oxytetracycline) in weaned piglets feed. (c) 2006 Elsevier B.V. All rights reserved.