Perch Positioning Affects both Laying Hen Locomotion and Forces Experienced at the Keel
Center for Animal Welfare, Department of Animal Science, University of California, Davis, CA 95616, USA
Center for Proper Housing: Poultry and Rabbits, Animal Welfare Division, University of Bern, 3052 Zollikofen, Switzerland
Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
Author to whom correspondence should be addressed.
Received: 27 May 2020 / Revised: 25 June 2020 / Accepted: 3 July 2020 / Published: 18 July 2020
Keel bone fractures in laying hens can occur due to falls and collisions within the housing system, although other factors such as genetics and nutrition contribute to the high fracture prevalence found in commercial laying hens. In addition, routine behaviors such as dustbathing or locomotion might contribute to the problem due to accumulated forces at the keel. To understand how locomotion affects the risk to sustain a fracture, we trained 20 brown and 20 white laying hens to jump from a platform to a perch installed at different angles, distances, and directions. We found that longer distances and steeper angles—especially during downward transitions—resulted in higher force at the keel and were more difficult for the hens to navigate. Our results show that perch position has an impact on the forces which a keel bone needs to absorb during controlled movements. In addition, perch position affects the hens’ ability to move safely from perch to perch, i.e., without falls and collisions. Optimizing perch position could help to create a safer environment for laying hens and might reduce keel bone fractures.