摘要

在断奶仔猪日粮中添加药理剂量的氧化锌（ZnO）可改善生长性能。然而，它会导致环境污染并诱导细菌产生抗生素抗性，这种做法仍有争议。比较常规锌源ZnO（分别为110和2,400 mg / kg Zn）与替代ZnO源(110和220 mg / kg Zn)对断奶仔猪肠道微生物群和完整性的影响。将四种处理中的每一种施用于四个围栏（两个仔猪/猪栏;断奶年龄，20天）15天，并且在第15天对仔猪取样以确定肠完整性指数。与110 mg / kg（分别为-1.7和-1.4 log10 cfu / g）的常规ZnO相比，饲喂2,400 mg / kg Zn的常规ZnO减少了远端小肠中的大肠杆菌和大肠杆菌，而替代ZnO只减少了大肠杆菌，不论剂量（-1.6至-1.7 log10 cfu / g）。与喂食110 mg / kg Zn常规ZnO的组相比，喂食替代ZnO源的猪的远端小肠粘膜的跨上皮电阻更高，这与claudin-1和zona occludens-1表达基因更高的趋势一致。有趣的是，110和220 mg / kg Zn的替代ZnO源与110 mg / kg Zn的常规ZnO相比增加了肠碱性磷酸酶基因转录物，而110 mg / kg Zn的替代ZnO源在粘膜中显示出更高的Zn浓度（与110mg / kg Zn（1,211μg/ g）的常规ZnO相比，2,520μg/ g）。然而，评估碱性磷酸酶活性，未发现显着影响。总之，替代的ZnO减少了消化嗜酸杆菌的数量并改善了肠道完整性，尽管相似或更好，取决于剂量，与常规ZnO的药理剂量的影响。

Zinc oxide (ZnO) supplied at pharmacological dosage in diets of weaned piglets improves growth performance. However, it causes environmental contamination and induces bacterial antibiotic resistance, yet this practice is debated. The effects on gut microbiota and integrity in weaned piglets of conventional ZnO at nutritional and pharmacological dosage (110 and 2,400 mg/kg Zn, respectively) were compared to an alternative ZnO source at 110 and 220 mg/kg Zn. Each of the four treatments was applied to four pens (two piglets/pen; weaning age, 20 days) for 15 days, and piglets were sampled on day 15 to determine indices of gut integrity. Feeding conventional ZnO at 2,400 mg/kg Zn reduced coliforms and Escherichia coli in distal small intestine as compared to conventional ZnO at 110 mg/kg (-1.7 and -1.4 log10 cfu/g, respectively), whereas the alternative ZnO reduced only coliforms, irrespective of dosage (-1.6 to -1.7 log10 cfu/g). Transepithelial electrical resistance of distal small intestinal mucosa was higher for pigs fed the alternative ZnO source as compared with groups fed 110 mg/kg Zn of conventional ZnO, in line with a trend for higher gene expression of claudin-1 and zona occludens-1. Interestingly, the alternative ZnO source at 110 and 220 mg/kg Zn increased intestinal alkaline phosphatase gene transcript as compared to conventional ZnO at 110 mg/kg Zn, whereas the alternative ZnO source at 110 mg/kg Zn exhibited higher Zn concentrations in mucosa (2,520 μg/g) as compared to conventional ZnO at 110 mg/kg Zn (1,211 μg/g). However, assessing alkaline phosphatase activity, no significant effects were found. In conclusion, the alternative ZnO reduced digesta Enterobacteriaceae numbers and improved gut integrity, albeit similar or better, depending on the dosage, to the effects of pharmacological dosage of conventional ZnO.

https://www.ncbi.nlm.nih.gov/pubmed/30298533