Effects of Different Hay Feeders, Availability of Roughage on Abnormal Behaviors and Cortisol Circadian Rhythm in Horses Kept in Dry Lots.
Authors: Carvalho Seabra Jéssica, Hess Tanja, Martinez do Vale Marcos, Spercoski Katherinne Maria, Brooks Ryan, Dittrich João Ricardo
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Hay Feeder Systems and Equine Behaviour in Dry Lot Housing Researchers compared three feeding systems—free-choice hay, slow feeders, and automated box feeders—to understand their effects on behavioural time budgets, abnormal behaviours, and stress physiology in 15 polo horses maintained in dry lots over a three-month Latin square design study. Free-choice feeding resulted in substantially higher hay consumption (16.6 kg daily) and waste compared with slow feeders (9.3 kg) and box feeders (10.4 kg), alongside significant weight gain of 23.5 kg over 15 days, whereas restricted-access systems produced minimal weight changes. Horses using free-choice and slow-feeder systems maintained natural foraging patterns, spending over 50% of their time eating—similar to grazing behaviour—yet box feeder systems, whilst reducing intake time, paradoxically increased undesirable behaviours including ground sniffing, coprophagy, and aggression, whilst promoting excessive standing. Importantly, cortisol circadian rhythms remained unaffected across all three systems, suggesting that stress physiology was not compromised by any feeding method, though the behavioural and economic trade-offs between waste reduction and psychological welfare merit careful consideration when selecting feeders for dry lot management.
Read the full abstract on PubMed
Practical Takeaways
- •Slow feeders offer a middle ground: they reduce hay waste and weight gain compared to free choice while maintaining natural foraging behaviors that minimize stereotypies and aggression
- •Box feeders significantly increase undesirable behaviors (aggression, coprophagy) despite time efficiency, suggesting the welfare cost may outweigh feed waste savings in dry lot systems
- •Feeder choice should prioritize behavioral welfare over feed efficiency alone; horses on restricted feeders spend surplus time on abnormal behaviors rather than resting
Key Findings
- •Free choice hay resulted in 16.6 kg daily consumption and 23.5 kg weight gain over 15 days, compared to 10.4 kg and 1.2 kg with box feeders (P < 0.001)
- •Slow feeders and free choice hay generated foraging time budgets >50% similar to grazing, while box feeders reduced eating time (P < 0.001)
- •Box feeder horses showed highest aggression (P < 0.043) and increased coprophagy and ground sniffing behaviors despite reduced eating time
- •Cortisol circadian rhythm was not significantly different among feeder types, indicating stress levels remained comparable