Chinese research looked into the effects of montmorillonite -zinc oxide hybrid on performance, diarrhoea, intestinal permeability and morphology of weanling pigs.
Montmorillonite is an organic clay and incorporate with zinc oxide a montmorillonite - zinc oxide hybrid (MMT-ZnO) is formed.
For the trial a total of 180 piglets (Duroc × Landrace × Yorkshire, average initial weight of 7.2 ± 0.3 kg weaned at 27 ± 1 d age) were randomly allotted to five groups for two weeks, each of which has six pens with six pigs per pen.
The dietary treatments were:
(1) basal control diet, 100 mg/kg of supplemental Zn as ZnSO4;
(2) basal diet + 2.0 g/kg montmorillonite (MMT), equivalent to the MMT in the MMT-ZnO treatment;
(3) basal diet + 500 mg/kg of Zn as ZnO;
(4) basal diet + 500 mg/kg of Zn as MMT-ZnO;
(5) basal diet + 2000 mg/kg of Zn as ZnO.
The results showed that supplemental 500 mg/kg of Zn from MMT-ZnO or 2000 mg/kg of Zn from ZnO
- improved average daily gain and daily feed intake,
- decreased faecal scores at 7 and 14 d postweaning,
- reduced plasma d-lactate and diamine oxidase activity,
- improved villus height and the villus height:crypt depth ratio at the jejunal mucosa
As compared with the control, MMT or 500 mg/kg of Zn from ZnO.
Pigs fed with 500 mg/kg of Zn as MMT-ZnO had lower plasma levels of d-lactate than those fed with 2000 mg/kg of Zn as ZnO.
Pigs fed with 500 mg/kg of Zn as MMT-ZnO had lower number of intestinal Clostridium and Escherichia coli than those fed with the control, MMT or 500 mg/kg of Zn as ZnO.
Supplementation with 2000 mg/kg of Zn as ZnO reduced the number of Clostridium in proximal colon as compared with the control while had no influence on intestinal E. coli.
Supplemental MMT or 500 mg/kg of Zn from ZnO had no effect on growth performance, intestinal microflora, permeability and morphology as compared to the control group.
The results indicated that dietary addition of 500 mg/kg of Zn from MMT-ZnO was comparable to 2000 mg/kg of Zn from ZnO while more effective than MMT or 500 mg/kg of Zn from ZnO for enhancing growth performance, alleviating diarrhoea, as well as improving intestinal microflora, mucosal barrier integrity and morphology of weaned pigs.