Abstract: Finding feeding strategies that meet horses' needs without compromising health is essential for optimising welfare, particularly in group housing, where limited hay availability increases aggression and injury risks. Recently, two strategies have emerged: portioning daily intake into smaller, frequent meals using time-controlled hay racks, or slowing intake with "slow-feeders." However, the effects of such management practices on horse behaviour remain underexplored. We conducted a cross-over study with 18 mares divided into four groups to compare three feeding strategies: "traditional" (3 of 2-hours meals during daylight, TD), "portioned" (6 of 1-hour meals spread over 24h, PO) and "slow-feeding" (ad libitum hay covered by a net, SF). Each treatment included 3 weeks of habituation and 2 weeks of data collection. We continuously recorded social interactions for 15 hours and noted the position and activity of all horses every 15 minutes. We also recorded injuries periodically and measured the lying behaviour using accelerometers. We analysed the effects of treatment on agonistic and affiliative behaviour within groups using generalised mixed model and selected the best model using AIC. We used the same procedure for the injuries and lying behaviour at the individual level. Horses in SF exhibited activity time budgets resembling natural conditions, while TD and PO resulted in time budgets similar to box-stall systems, despite the loose-housing system. Surprisingly, our results suggest that PO may be more frustrating for the horses than TD. Indeed, there was no significant reduction of agonistic behaviours during feeding times in PO compared to TD and lying behaviour tended to be impaired in PO (-11.3 min/day, 95% CI [-25.8; 3.1]) compared to SF and TD (37.5 min/day on average). In our study, portioning into smaller, more frequent meals did not reduce the stress in horses. This highlights the need for further research on portioning strategies to find optimal feeding management. In addition, slow-feeding was a more suitable feeding strategy for horses than portioning. However, more research is required to substantiate the initial findings on the efficacy of ad libitum slow-feeding on the horse's health and behaviour.
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The research sought to investigate the effects of different feeding strategies on the welfare and behaviour of horses kept in groups. The strategies examined included traditional feeding, portioned feeding, and slow-feeding methods. The results suggest that slow-feeding appeared most conducive to natural behaviour, while portioned feeding appeared to cause the most stress, contrary to expectations.
Study Design and Procedure
The experimental study was conducted using 18 mare horses categorized into four groups. Each group was subjected to different feeding strategies: Traditional feeding (3 two-hour meals during daylight), portioned feeding (6 one-hour meals spread over 24 hours), and slow-feeding ( unending hay covered by a net).
Each feeding method was subjected to a 3-week habituation period, followed by a 2-week data collection period.
The researchers recorded social interactions continuously for 15 hours and observed the position and activity of all horses every 15 minutes. Injuries were also recorded periodically, while lying behavior was measured using accelerometers.
The collected data was analyzed using a generalized mixed model, selected based on the Akaike Information Criterion (AIC), to examine the effects of different feeding strategies on within-group agonistic and affiliative behaviour.
Main Findings
Horses subjected to the slow-feeding strategy exhibited activity time budgets that closely resembled natural conditions. In contrast, horses in the traditional and portioned feeding groups displayed time budgets that were similar to those observed in box-stall systems, even when in a loose-housing system.
Contrary to expectations, the horses subjected to the portioned feeding strategy exhibited high levels of stress, without any significant reduction in agonistic behavior during feeding times, as compared to the traditional feeding group. Furthermore, lying behavior in the portioned feeding group appeared to be slightly impaired.
Portioned feeding resulted in little to no reduction of stress in horses, suggesting the need for further research to find the most effective feeding management and strategy.
Conclusions
Slow-feeding emerged as a more suitable feeding method for horses as compared to portioned feeding, reinforcing the importance of allowing a horse to feed at its natural pace.
However, further research is required to consolidate the initial findings and examine the effects of ad libitum slow-feeding on horse health and behavior.
Cite This Article
APA
Roig-Pons M, Bachmann I, Freymond SB.
(2025).
Impact of feeding strategies on the welfare and behaviour of horses in groups: An experimental study.
PLoS One, 20(6), e0325928.
https://doi.org/10.1371/journal.pone.0325928
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