Welfare and health aspects of free ranges for laying hens

Abstract

In the Netherlands, 29% of laying hens have access to a free range, because of the possibilities for natural behaviour, additional space and fresh air. Daily access to the range appears to be related to less feather pecking damage and fewer pecking wounds, i.e. better animal welfare. On average, no more than 47% of the hens in a flock go outside simultaneously. Range use is higher in the case of brown hens, smaller flocks, with roosters, in sheds with natural ventilation and in flocks with better plumage. In ranges where at least 8% of the surface is covered with trees or shrubs, fewer wild waterbirds are seen; species that pose a risk for avian influenza. In landscapes with more trees or woody elements, also fewer waterbirds are seen around chicken runs than in open landscapes. Of the chickens found dead in the range, 73% were probably killed by a bird of prey and 9% by a fox. A survey shows that an average of nearly 4% of hens with a range are lost to predation, out of a total mortality of 12%. Few or no eggs of chicken parasites were found in the soil of the free ranges. No relationship was found between worm infection on the one hand and range use, health, mortality and production on the other. From research on organic flocks in Sweden, the Netherlands and Italy, it appreared that only Dutch flocks were dewormed, but generally they had as many worm infections as the foreign flocks that were not dewormed. Overall, this thesis supports the assumption that free range use contributes to the welfare of laying hens. Practical recommendations or suggestions for further research are made for the investigated risks to animal welfare.