The effects of copper/zinc-loaded montmorillonite (Cu/Zn-Mt) on growth performance, intestinal barrier and gut microbiota of weaned pigs were investigated in the present study. A total of 108 piglets (Duroc × Landrace × Yorkshire; 6.36 kg; weaned at 21 ± 1 d age) were used in this experiment. The pigs were randomly assigned to three treatments with six replicates, six pigs in each replicate. The three treatments were as follows: (1) control group: basal diet; (2) Cu/Zn-Mt group: basal diet supplemented with 39 mg/kg Cu and 75 mg/kg Zn as Cu/Zn-Mt; and (3) Cu +Zn +Mt group: basal diet supplemented with the mixture of copper sulphate, zinc sulphate and montmorillonite (equivalent to the copper and zinc in the Cu/Zn-Mt treatment). The results indicated that, compared with the pigs from control group, average daily gain and gain: feed ratio were increased and the faecal score on days 7 and 14 after weaning was decreased by supplementation of Cu/Zn-Mt; intestinal transepithelial electrical resistance (TER) and expressions of tight junction protein claudin-1 and zonula occludens-1 were increased, and intestinal permeability of fluorescein isothiocyanate-dextran 4 kDa was decreased by supplementation with Cu/Zn-Mt. According to the Illumina-based sequencing results, Cu/Zn-Mt supplementation increased the relative abundance of core bacteria (Lactococcus, Bacillus) at genus level and decreased the potentially pathogenic bacteria (Streptococcus and Pseudomonas) in colon of weaned piglets. However, the piglets fed with the mixture of copper sulphate, zinc sulphate and montmorillonite showed no effects in above parameters in comparison with the pigs from control group. In conclusion, dietary Cu/Zn-Mt could improve growth performance, decrease the diarrhoea and improve intestinal barrier and bacterial communities of weaned pigs. The results indicated that ‘loading’ of montmorillonite with Zn and Cu changed not only its chemical but also its nutritional properties.

中文翻译：

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日粮含铜/锌蒙脱石可改善断奶仔猪的生长性能和肠道屏障并改变肠道微生物群

本研究调查了负载铜/锌的蒙脱石 (Cu/Zn-Mt) 对断奶仔猪生长性能、肠道屏障和肠道微生物群的影响。本实验共使用 108 头仔猪（杜洛克 × 长白 × 约克夏；6.36 公斤；在 21 ± 1 日龄断奶）。将猪随机分配到三个处理组，每组六个重复，每个重复六头猪。三个处理如下： (1)对照组：基础饮食；(2)Cu/Zn-Mt组：基础日粮添加39 mg/kg Cu和75 mg/kg Zn作为Cu/Zn-Mt；(3)Cu+Zn+Mt组：基础日粮添加硫酸铜、硫酸锌和蒙脱石的混合物（相当于Cu/Zn-Mt处理中的铜和锌）。结果表明，与对照组猪相比，平均日增重和增重：断奶后第 7 天和第 14 天的饲料比例增加，粪便评分通过补充 Cu/Zn-Mt 降低；通过补充 Cu/Zn-Mt，肠道跨上皮电阻 (TER) 和紧密连接蛋白 claudin-1 和 zonula occludens-1 的表达增加，并且异硫氰酸荧光素-葡聚糖 4 kDa 的肠道通透性降低。根据基于 Illumina 的测序结果，补充 Cu/Zn-Mt 增加了核心细菌的相对丰度（通过补充 Cu/Zn-Mt，荧光素异硫氰酸酯-葡聚糖 4 kDa 的肠道通透性降低。根据基于 Illumina 的测序结果，补充 Cu/Zn-Mt 增加了核心细菌的相对丰度（通过补充 Cu/Zn-Mt，荧光素异硫氰酸酯-葡聚糖 4 kDa 的肠道通透性降低。根据基于 Illumina 的测序结果，Cu/Zn-Mt 的补充增加了核心细菌的相对丰度（乳球菌属、芽孢杆菌属），并减少断奶仔猪结肠中的潜在致病菌（链球菌和假单胞菌）。然而，与对照组的猪相比，饲喂硫酸铜、硫酸锌和蒙脱石混合物的仔猪对上述参数没有影响。总之，日粮Cu/Zn-Mt可以提高断奶仔猪的生长性能，减少腹泻，改善肠道屏障和细菌群落。结果表明，用锌和铜“加载”蒙脱石不仅改变了其化学性质，而且改变了其营养特性。