Inhibitory effect of high‐dosage zinc oxide dietary supplementation on C ampylobacter coli excretion in weaned piglets

Aims This study investigated the impact of zinc oxide ( Z n O ) on C ampylobacter coli by in vivo and in vitro assays. Methods and Results By in vitro growth inhibition assays, a high susceptibility of C amp. coli against Z n O could be observed. At concentrations ≥2·6 mmol l −1 Z n O , a decline in cell numbers occurred. Quantitative real‐time PCR assays demonstrated an up‐regulation of the main oxidative stress gene ( katA ) in response to Z n O treatment. The expression level of katA was increased by fivefold after Z n O treatment. An experiment was carried out in pigs to elucidate the impact of Z n O as feed supplement on C amp. coli faecal excretion. Feeding a high‐dosage Z n O concentration (3100 mg kg −1 ) to piglets significantly reduced the faecal excretion of C amp. coli by up to 1 log CFU g −1 as compared to animals receiving a low (40 mg kg −1 ) or medium (100 mg kg −1 ) Z n O diet. Conclusion In vitro assays showed a high susceptibility of C amp. coli against Z n O . Adding high levels of Z n O to the diet of weaned piglets reduced C amp. coli excretion significantly. There is evidence for the induction of an oxidative stress response by Z n O supplementation in C amp. coli . Significance and Impact of the Study Supplementation of a high‐dosage Z n O diet to piglets can reduce the C amp. coli load, potentially leading to a lower contamination risk of meat during slaughter.