竹酢粉对断奶仔猪肠道组织形态与机体免疫基因表达的影响

（Objective）The aim of this study is to explore the effects of bamboo vinegar powder on intestinal morphology and immunity-related mRNA genes expression of weaned piglets so as to ascertain possible mechanism of action of bamboo vinegar powder to piglets.(Method) Forty-five crossbred(Duroc×Landrace×Yorkshire) weaned piglets (all male, body weight 6.74±0.17kg) at 31 days of age were randomly assigned to 5 treatments with 3 replicates per treatment and 3 piglets in each replicate. The five treatments were as follows: CON(a basal diet), ANT(the basal diet+ antibiotics), BV1(the basal diet+ 0.1%bamboo vinegar powder), BV5(the basal diet+ 0.5%bamboo vinegar powder), BV10(the basal diet+ 1%bamboo vinegar powder). This experiment lasted 35 days. Two piglets per replicate were sacrificed to obtain samples and further test.(Result) The results showed bamboo vinegar powder added in weaned piglets' diets significantly decreased crypt depths of small intestinal segments(P<0.05) and significantly increased the ratio of villus height to crypt depth (P<0.05). TNF-α, IL-1β, IL-6 mRNA expression levels in duodenum of bamboo vinegar powder treatment groups tended to lower (P<0.1) and IL-6 mRNA expression levels in spleen of these groups significantly descended (P<0.05). TNF-α, IL-1β mRNA expression levels in liver of BV5 were significantly raised (P<0.05) indicating that immune activity of natural killer cells in liver were enhanced. TNF-α, IL-6 mRNA expression levels in mesenteric lymph nodes of BV10 were significantly lower than normal (P<0.05) consisting with high diarrhea rate in this treatment. (Conclusion) Overall, bamboo vinegar powder could improve intestinal morphology and ameliorate immune state by regulating immunity-related genes expression. In conclusion, bamboo vinegar powder had the potential to replace antibiotics to be growth enhancer for weaned piglets and its appropriate dosage was 0.5%.