Abstract:

Seventy-two piglets (Duroc×Large White×Landrace) weaned at 21 days weighting (5.06±0.49)kg were used to study the effects of chlortetracycline on the activity of intestinal nuclear factor NF-κB for a period of 15 days. The piglets were randomly allotted to three groups, each of which was replicated three times with eight pigs per replicate. The piglets were reared on a conventional corn-based diet supplemented with 0(control group), 75mg/kg(test 1) and 150mg/kg chlortetracycline(test 2). All piglets were given ad libitum access to both feed and water. The results showed that supplementation of chlortetracycline 75mg/kg and 150mg/kg significantly increased AFI by 3.62% and 8.35%（P<0.05） and decreased diarrhea rate by 22.10% (P<0.05) and 52.23%（P<0.01）respectively over the control group. The lengths of the villus within the jejunal and ileal sections of the small intestine were increased significantly (P<0.05) and the crypt depth were decreased significantly (P<001) relative to control group. The activity of NF-κB in jejunum of weaning piglets were decreased 41.57%（P<0.05）and 91.01%（P<0.01） and IκK-β mRNA expression decreased 56.16%（P<0.05）and 89.72%（P<0.01）in test 1 and test 2 group respectively. Nuclear factor NF-κB and IκB kinase（IκK-β） may play an important role in the modulation of macrophage and functions of digestive tract in weaning piglets