日粮抗生素影响断奶仔猪肠道结构的机理研究

Approach on the mechanisms of effects of chlortetracycline in the diet on intestinal morphology in weaning piglets

以21日龄杜大长断奶仔猪为研究对象,探讨了日粮中抗生素(金霉素)对肠道结构和细胞因子的影响。结果表明,在断奶仔猪日粮中添加75和150 mg/kg金霉素,显著提高空肠和回肠组织绒毛长度,显著降低隐窝深度。日均采食量分别提高3.62%和8.35%(P<0.05),腹泻率分别下降22.10%和52.23%(P<0.01);血清中TNF-α水平下降28.78%(P<0.05)和78.29%(P<0.01),IL-6水平下降12.85%和83.40%(P<0.01);空肠黏膜核因子NF-κB活性分别下降41.57%(P<0.05)和91.01%(P<0.01),IκK-βmRNA水平分别下降56.16%(P<0.05)和89.72%(P<0.01)。结果提示,日粮中金霉素可能通过调控肠道粘膜组织核因子抑制蛋白激酶IκK-βmRNA水平,抑制核因子NF-κB的活化和核移位,进而影响肠道炎症因子的表达,改善断奶仔猪肠道粘膜的形态和结构,提高了采食量,降低腹泻率。

Seventy-two piglets （Duroc × Large white × Landrace） weaned at 21 days were used to study the effects of chlortetracycline on intestinal morphology and cell structure in weaning piglets. The piglets were randomly allotted to three groups, each of which was replicated three times with eight pigs per replication. The piglets were reared on a conventional corn-based diet added by 0 （control group）, 75 mg/kg （test 1 ）, and 150mg/kg ehlortetracycline （test 2）. All piglets were given ad libitum access to both feed and water. The results showed that addition of 75mg/kg and 150mg/kg chlortetracycline 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, as compared with the control group. The lengths of the villi 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） as compared with the control group. Addition of 75mg/kg and 150mg/kg chlortetracychne decreased the activities of NF-κB in jejunum by 41.57 % （ P 〈 0.05）and 91.01% （ P 〈 0.01 ）, and decreased IκK-β mRNA expression 56.16 % （ P 〈 0.05）and 89.72 % （ P 〈 0.01, respectively. Nuclear factor NF-κB and IκB kinase may play an important role in the modulation of macmphage and functions of digestive tract in weaning piglets.