Moving hens into cages affects cognitive performance, extinction learning and motivation for rewards

Area of Science:

• Animal Cognition
• Animal Welfare Science
• Ethology

Background:

• Understanding chicken cognition is crucial for enhancing welfare in production systems.
• Barren housing conditions can negatively impact animal welfare, leading to deficits in affective states and cognition, particularly in young animals.
• Limited research exists on the cognitive effects of barren environments on adult laying hens.

Purpose of the Study:

• To investigate if adult hens transferred to battery cages exhibit lower cognitive performance compared to those housed cage-free.
• To explore the modulating effect of individual personality traits on cognitive responses to housing conditions.

Main Methods:

• Sixty hens were reared in enriched aviaries, with half transferred to battery cages (456 cm²/hen) and the remainder kept cage-free (5,333 cm²/hen) for 64 days.
• Personality was assessed using four standardized tests.
• Spatial memory was evaluated using a modified hole-board task, calculating working memory (WM), general working memory (GWM), and reference memory (RM).
• Extinction learning was assessed by recording responses to reward omission after baited rewards were consumed.

Main Results:

• Battery-housed hens outperformed cage-free hens in all memory metrics (WM, GWM, RM).
• Battery-housed hens displayed increased activity and engagement during the post-reward period, suggesting higher reward motivation.
• A deficit in extinction learning was observed in battery-housed hens.
• More fearful hens exhibited lower WM and GWM and slower task acquisition.

Conclusions:

• Housing conditions and personality traits interact to shape cognitive performance in laying hens.
• Enhanced cognitive performance in battery cages may be linked to increased motivation for food rewards rather than improved welfare.
• The findings suggest that apparent cognitive improvements under poor housing conditions may mask underlying welfare compromises, such as deficits in adaptive learning.