The so-called "spent hens" are processed in special processing plants. Typical for these birds is a matured skeleton (little cartilage), which is very weak because the egg production caused a lack of calcium (Osteoporose), and because they (especially the battery-birds) had little physical exercise. Before and during processing, many bones are therefore broken. Also typical is the pronounced keel bone.
The meat of spent hens is generally used for consumption as whole birds, or parts with breast meat going into added value products while the rest of the bird is exported to third countries. Alternatively, the meat is used for soup production, and combs can be harvested for medical and pharmaceutical purposes. The mature eggs are harvested during the evisceration process and further processed into products such as mayonnaise.