Improving the welfare of laying hens during the catching, handling, and crating process at depopulation

Principal Investigator: Michael Toscano
Project Team: Hanno Würbel (official supervisor)
Ariane Stratmann (PostDoc)
Christopher Gerpe (PhD student)
Collaborator: Urs Geissbühler (
Bernhard Voelkl (PostDoc)
Rupert Bruckmaier (Prof.)
Funded by: Swiss Federal Food Safety Veterinary Office (FSVO)


Depopulation in laying hens is known to be a stressful and potentially harmful process where injuries such as bone fractures or joint dislocations are common. To date, virtually all of the data known about depopulation comes from investigations of caged systems. Given the much greater complexity and difficulties in handling and collecting hens within aviaries, there is concern that aviaries may present an even greater problem. As depopulations are conducted under minimum light conditions, so that the hens stay calm, operating in complex systems becomes even more difficult. On the other hand aviaries do provide better conditions for the hens. Separated areas such a sleeping area with perches, nest boxes or free ground space allow the animals to pursue their needs in a much better way. It is therefore our aim to improve aviary systems instead of propagating a return to caged systems. In a first phase we intend to identify the types and frequency of injuries, physiological changes indicating stress and their cause. In a second phase we will try to optimize the depopulation process by developing and evaluating new strategies and tools that are thought to reduce the harmful aspects of depopulation. While improving the welfare of the hen is of primary importance, another aspect is the improvement of working conditions for the catchers. Hens are loaded by hand, which after some hours in an often hot and dusty environment, can become difficult. As tiredness increases and concentration decreases hens are more likely to get hurt as they accidentally hit on the pen furniture or as they fall after slipping a person’s grip. When people are tired they are also more likely to hurt themselves therefore it is essential to facilitate the work which will improve conditions for the catchers as well as animal welfare by reducing the rate of injuries.