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

ABSTRACT

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, where 12 were classified as having sharp beaks (SB) and 12 as having blunt beaks (BB).

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. SB hens removed more feathers from the model and had a greater change in skin weight than BB hens. The mean number of pecks made at the model did not differ between the beak shape groups; however, SB hens had a greater percentage of successful pecks, resulting in feather and/or tissue removal, compared to BB hens.

5. In conclusion, SB hens were more capable of removing feathers and causing damage. Birds performed more successful pecks resulting in feather and/or tissue removal as they gained experience pecking at the model.

KEYWORDS:

• Morphology
• severe feather pecking
• welfare
• cannibalism
• egg production

Acknowledgments

Thank you to British Poultry Science Ltd. for providing a small project grant to fund this study. Thank you to Dr Parvez Alam from the University of Edinburgh’s School of Engineering for providing the video camera. Thank you to JSR Services for donating the hens and to the SRUC Allermuir farm staff for their assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Video data are available from the University of Edinburgh’s DataShare at https://doi.org/10.7488/ds/3838.

Additional information

Funding

The author SS is supported by a Research Excellence Grant at Scotland’s Rural College (SRUC), the Flexible Talent Mobility Award scheme, and Lohmann Breeders. VS receives funding from the Scottish Government Rural Affairs, Food, and the Environment (RAFE) strategic research portfolio 2022-2027. ICD and JJS receive BBSRC institution strategic programme grant support [BBS/E/D/30002275, BBS/E/D/30002276]. None of the funding sources were involved in the design of the study; in the analyses or interpretation of data; in the writing of the manuscript; or in the decision to submit the article for publication.