Behavioral and Transcriptomic Fingerprints of an Enriched Environment in Horses (Equus caballus).
Authors: Lansade Léa, Valenchon Mathilde, Foury Aline, Neveux Claire, Cole Steve W, Layé Sophie, Cardinaud Bruno, Lévy Frédéric, Moisan Marie-Pierre
Journal: PloS one
Summary
# Editorial Summary: Environmental Enrichment and Equine Development A 12-week comparison of conventionally housed young horses against those provided with extensive enrichment—including pasture access, varied feedstuffs, novel objects, and sensory stimuli—revealed significant shifts in personality traits alongside measurable changes in stress physiology and gene expression. Enriched horses demonstrated reduced fearfulness, altered reactivity to human handlers, and lower sensory sensitivity, with personality changes remaining evident three months after the intervention ended, suggesting durable developmental effects rather than temporary behavioural responses. Blood transcriptomic analysis showed that enriched horses upregulated genes associated with cell growth and proliferation whilst downregulating apoptosis markers, alongside reduced cortisol levels—a molecular signature indicating genuinely improved physiological wellbeing rather than mere behavioral adaptation. Enriched horses also performed better on cognitive testing (Go/No-Go tasks), suggesting the environmental complexity enhanced learning capacity alongside welfare. For practitioners, these findings support the integration of pasture time, variable forage presentation, and novel stimuli as evidence-based components of rearing and management protocols that shape not only how young horses behave around people and objects, but their fundamental stress resilience and adaptive capacity into adulthood.
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Practical Takeaways
- •Enriched housing with pasture access, varied feeding, and environmental stimulation produces measurable improvements in horse personality (reduced fearfulness, better human reactivity) that persist months after treatment ends
- •Environmental enrichment enhances learning capacity and cognitive performance—horses exposed to varied stimuli learn faster, suggesting training may be more effective with enriched management
- •Enrichment provides stress reduction benefits with measurable physiological markers; consider pasture time, varied feed presentation, and novel objects/sensory experiences as practical welfare investments with lasting effects
Key Findings
- •Environmental enrichment modified three personality dimensions: fearfulness, reactivity to humans, and sensory sensitivity, with changes persisting >3 months post-treatment
- •EE-treated horses demonstrated better learning performance in Go/No-Go cognitive tasks compared to control horses
- •Whole-blood transcriptomic analysis revealed EE induced expression of genes involved in cell growth and proliferation while control treatment activated apoptosis-related genes
- •Reduced cortisol levels and stress indicators in EE-treated horses indicated improved well-being alongside behavioral and molecular changes