Evaluating a novel automatic feeding device for hay provision in horses: behavioral outcomes in group and individual housing.

Evaluating a novel automatic feeding device for hay provision in horses: behavioral outcomes in group and individual housing

Overview of the Study

• This research investigated how a new automatic feeding device (AFD) affects the behavior of horses when providing hay, both in group settings and when horses are housed individually.
• The aim was to understand how different feeder operation modes influence foraging behavior, stress-related behaviors, and social dynamics among horses.

Study Design and Methods

• The study was conducted in two phases:
• Phase 1 (P1): Involved three mares housed together to observe behaviors under three conditions:
  • Control-Hay: traditional feeding with hay directly placed on the ground.
  • O-AFD (Open AFD): feeder continuously open, allowing free access to hay.
  • OC-AFD (Open/Closed AFD): feeder alternating between open and closed periods.
• Phase 2 (P2): Involved four individually housed horses to test different AFD schedules:
  • LO-OP (Long Opening): feeder open for a long duration.
  • ME-OP (Medium Opening): feeder open for a medium duration (40 min open, 20 min closed).
  • SH-OP (Short Opening): feeder open for a short duration.
• Continuous video recordings were used to capture behavioral data.
• Statistical analysis employed linear mixed-effects models and principal component analysis to evaluate effects and variability.

Key Findings from Group-Housed Horses (Phase 1)

• Behavioral differences: Individual horses exhibited varying levels of foraging and agonistic (conflict) behaviors.
• Exploratory Behaviors: Significantly increased when the feeder alternated between open and closed (OC-AFD) compared to being continuously open (O-AFD) (approx. 3.93 min/h vs. 1.72 min/h), suggesting increased interaction or searching behavior during closed periods.
• Residual Hay: Feeding via AFD resulted in leftover hay:
  • O-AFD left approximately 3.98 kg residual hay.
  • OC-AFD left more residual hay (~4.88 kg).
  • In contrast, ground feeding (Control-Hay) left no residual hay.
• Social Hierarchy Impact: Dominance relationships strongly influenced which horses gained access to the AFD, demonstrating that social rank affected feeding opportunities.

Key Findings from Individually Housed Horses (Phase 2)

• Foraging Duration: Time spent eating hay decreased progressively with shorter feeder open durations:
  • LO-OP: ~46.9 minutes/hour.
  • ME-OP: ~42.8 minutes/hour.
  • SH-OP: ~38.8 minutes/hour.
• Stress-Related Behaviors: These increased as the feeder open time shortened:
  • Pawing behaviors were up to 7-8 times more frequent during SH-OP compared to LO-OP and ME-OP.
  • Rubbing and use of teeth or tongue on the feeder were 2-3 times higher in SH-OP.
• Residual Hay: Increased as access duration decreased, meaning shorter feeding periods led to more uneaten hay.
• Hay Intake Rate: Slightly reduced with shorter feeder openings, indicating less efficient consumption.

Interpretations and Implications

• The automatic feeder’s delivery schedule and operation method significantly influenced equine feeding and social behaviors.
• Social hierarchy must be considered when implementing feeders in group housing, as dominant horses may monopolize access.
• Short feeder open times, though regulating intake, may provoke stress-indicative behaviors in individually housed horses.
• The medium opening schedule (40 min open, 20 min closed) appears optimal, balancing:
  • Effective control of hay intake.
  • Maintenance of natural feeding behaviors.
  • Minimization of stress-related or agonistic behaviors.
• Some hay wastage is associated with AFD use, especially at shorter opening durations, which could impact feed efficiency and costs.

Conclusions

• This study provides preliminary evidence that tailored use of an automatic feeding device can support regulated hay provision in horses while considering behavioral welfare.
• Optimizing feeder access timing is crucial to reduce stress and social conflicts while maintaining natural foraging patterns.
• Further research could explore adaptations for group dynamics and efficiency improvements to minimize residual hay.