More Than Eggs - Relationship Between Productivity and Learning in Laying Hens

Area of Science:

• Animal behavior
• Cognitive ethology
• Animal genetics

Background:

• Intense selection for production traits in chickens, like egg laying, may lead to unintended behavioral changes.
• Energetic trade-offs from high productivity could potentially impact cognitive functions, such as learning performance.

Purpose of the Study:

• To investigate the hypothesis that highly productive laying hens exhibit reduced learning performance compared to moderately productive lines.
• To examine the influence of selection for productivity and phylogenetic origin on learning abilities in chickens.

Main Methods:

• Four chicken lines differing in laying performance (200 vs. 300 eggs/year) and origin were tested.
• A three-phase learning paradigm (initial learning, reversal learning, extinction) was employed using semi-automated Skinner boxes.
• Learning performance was measured by active decisions to reach criteria, analyzed with linear models and Kaplan-Meier survival analysis.

Main Results:

• A higher proportion of high-production hens met learning criteria across all phases compared to lower-production hens.
• High-production hens required fewer active decisions to achieve learning criteria in initial learning and extinction phases.
• Phylogenetic origin influenced learning performance specifically during the extinction phase.

Conclusions:

• Results contradict the initial hypothesis, indicating high-production hens possess better learning strategies in a feeding-rewarding context.
• Selection for productivity may enhance learning, possibly enabling efficient energy acquisition.
• Underlying mechanisms could involve neuronal differences or adaptations in foraging strategies and personality traits.