[Pathologic-anatomic investigations in laying hens in various housing systems]

Gross pathologic and histologic changes were investigated in a total of 1000 end-of-lay hens. Thirty animals were drawn from free range stocks, 270 from deep litter stocks, and 700 from caging systems. The following changes were evaluated with regards to housing systems: Pododermatitis, deformation of the keel bone and amputated beaks occurred primarily in free range hens. Deep litter hens also suffered from pododermatitis, keel bone deformation and amputated beaks in addition to pecking wounds. In caged hens severe fatty liver syndromes, injuries of the claws and inflammation of the feather follicles were mainly found. Furthermore, injuries and fractures due to handling and transport were almost exclusively found in caged hens. It has to be concluded that all of the investigated housing systems can predisposed hens to certain lesions. The documented changes--e.g. chronic inflammation, skelettal deformities and injuries--are painful and may lead to permanent alterations. Therefore, these changes should be condemned as conflicting with animal protection regulations.