Sows and their offspring were kept in flatdeck pens in the same stable, the stable and pens were cleaned daily. No animal showed signs of disease during the trial period. From 12 days of age, piglets had access to a commercial non-medicated prestarter diet which was formulated to meet require- ments of piglets with average body weight of 5–10 kg. After weaning, animals were randomly assigned to three treatment groups, kept in flatdeck pens with two animals per pen Weaned pigs were fed an antibiotic free commercial starter diet containing low (57 mg/ kg), intermediate (164 mg/kg) or high (2,425 mg/kg) zinc as analytical grade zinc oxide (Sigma Aldrich, Taufkirchen, Germany) to cover minimal to excessive dietary zinc supplementation.
On days 32, 39, 46 and 53 of life, seven pigs per group