Abstract
In conclusion chickens kept on free-range farms are exposed to high risks of nematode infections and have high mortality rates with no obvious link to parasite infections. Once the farm environment is contaminated with the nematode eggs, establishment and further spread of nematodes to the hens is a matter of time. This will latest be the case in the second production period, even if the hens are kept in a rotation system and in small herd sizes. This underlines the importance of nematode infections in all free-range systems.