Figure 1. Set-up of the Mallard Model.

Each experiment consisted of 4 generations of mallards with 2 individuals in each. The first generation of mallards was infected by esophageal inoculation with the A/Mallard/Sweden/50908/2006(H6N2) virus (day 0) and were put in the experimental room where the sole water source contained OC. The following generations were introduced with 3-day intervals allowing the infection to be fecal-orally transmitted between generations during two days. Five days after introduction, each generation birds were removed and euthanized. The water in the sole water source of the birds was changed daily and contained the same level of OC during each 14 day-experiment. Three subsequent experiments were performed with OC levels of 120 ng/L, 1.2 µg/L and 12 µg/L.