载铜蒙脱石对大肠杆菌和仔猪腹泻的影响

对通过阳离子交换反应合成的载铜蒙脱石 (MMT- Cu) ,应用 XRD衍射分析显示 ,载铜反应前后 ,蒙脱石的(0 0 1)面网间距从原先的 1.5 4 4 nm增加到了 1.5 88nm ,表明铜是以水合阳离子或复合阳离子形式进入蒙脱石晶格层间位置。体外试验表明 ,MMT- Cu对大肠杆菌 K88具有较强的抗菌能力。MMT- Cu对仔猪的试验表明 :与对照组相比 ,日粮中添加 0 .2 % MMT- Cu使仔猪日增重提高了 13.89% (P<0 .0 1) ,料重比下降了 8.38% (P<0 .0 5 ) ,平均腹泻率降低了 71.80 % (P<0 .0 1) ,结肠内容物中大肠杆菌数显著下降 (P<0 .0 1) ,空肠绒毛高度及绒毛高度与腺窝深度的比率分别提高了 19.2 1% (P<0 .0 5 )和 37.10 % (P<0 .0 1)。

Effects of Cu Bearing Montmorillonite on Escherichia coli and Diarrhea in Weanling Pigs

Cu bearing montmorillonite(Cu-MMT) was produced by Cu~(2 ) cation exchange reaction.XRD analysis showed that(001) basal spacing of the montmorillonite increased from 1.544 nm to 1.588 nm after Cu~(2 ) exchange.This indicated that Cu~(2 ) entered into interlayer position of montmorillonite as hydrated cation or composite cation.In vitro results indicated that Cu-MMT had stronger antibacterial activity on Escherichia coli K_(88).In the in vivo study,four replicates of eight weanling pigs were assigned to each of two dietary treatments to study the effects of Cu-MMT on Escherichia coli and diarrhea.As compared with control,supplementation with 0.2% Cu-MMT improved average daily gain by 13.89%(P<0.01) and decreased F/G by 8.38%(P<0.05).The mean diarrhea incidence decreased by 71.80%(P<0.01).The viable counts of Escherichia coli in colonic contents significantly reduced(P<0.01).Villus height and the villus height to crypt depth ratio at the jejunal mucosa increased by 19.21%(P<0.05) and 37.10%(P<0.01),respectively.