Examining the relationship between different naturally-occurring maxillary beak shapes and their ability to cause damage in commercial laying hens

1. Using “chicken” models to avoid unnecessary harm, this study examined the relationship between naturally-occurring maxillary (top) beak shapes and their ability to cause pecking damage.
2. A selection of 24 Lohmann Brown laying hens from a total population of 100 were sorted into two groups based on their maxillary beak shape: 12 were classified as having sharp beaks and 12 as having blunt beaks.
3. All hens were recorded six times in a test pen which contained a “chicken” model (foam block covered with feathered chicken skin) and a video camera. During each test session, the number of feathers removed from the model, the change in skin and block weight (proxies for tissue damage), and the percentage of successful pecks (resulting in feather and/or tissue removal) were recorded.
4. Sharp-beak hens removed more feathers from the model and had a greater change in skin weight than blunt-beak hens. The mean number of pecks made at the model did not differ between the beak shape groups; however, sharp beak hens had a greater percentage of successful pecks, resulting in feather and/or tissue removal, compared to blunt beak hens.
5. In conclusion, sharp-beak hens were more capable of removing feathers and causing damage. Birds also performed more successful pecks resulting in feather and/or tissue removal as they gained experience pecking at the model.