What the science supports

A Swedish review of 37 enrichment ideas used by horse owners found scientific backing for about half of them. Here is what the evidence supports, what can backfire, and where the research has yet to catch up.

Enrichment ideas travel fast around yards and across social media. Many of us will have been tempted to try tips ranging from providing branches to strip, filling hay balls, mounting mirrors on the walls, or playing a radio in the barn… Whilst many of these ideas are great, and we certainly support the need to enrich our horse’s lives in the stable, few of the methods have been tested in practice to see whether they meaningfully impact our equines’ wellbeing.

This gap did not go unnoticed, leading to a 2026 bachelor’s project at the Swedish University of Agricultural Sciences (SLU) in Uppsala. Emma Persson analysed three years of posts in a public Swedish Facebook group devoted to equine enrichment, which had 1065 members. She listed every method owners described, then checked each one against the published research.

What owners are doing

Owners in the group described 37 different enrichment methods. Most (62%) involved food. Branches, fresh or dried, were the most mentioned, tied with extra scratching opportunities such as brushes, mats and posts. Mixing edible extras into forage, hay balls, and introducing something new to the paddock followed in terms of popularity.

How much of it is backed by evidence?

Persson could link a clear function, such as longer chewing time or more foraging, to 18 of the 37 methods mentioned (49%). Food-based ideas fared slightly better (52%) in terms of evidence-backing than non-food ones (43%). Published evidence of an actual welfare effect existed for only 10 methods (27%).

Nineteen methods had no scientific support that she could find. These included frozen fruit lollies, dog toys, cardboard to tear up, obstacle courses on the way to the hay and adding a miniature horse to the herd. Persson is careful to say this does not mean they fail. It means nobody has studied them and that this is a gap worth looking at.

What the research supports

Slow feeders. French researchers observed 38 horses in their own stables, rotating them through three set-ups for three weeks each: hay on the floor, a hay bag on the wall and a slow feeder in the corner. Both devices made hay last longer. The hay bag, however, came with more frustration behaviour. The slow feeder reduced stereotypic behaviour, and the horses became friendlier towards people.

Hay nets, with care. Nets clearly extend eating time, but mesh size matters. A 2026 review summarised in the thesis linked small mesh (2.5 to 3.5 cm) with more frustration than larger mesh (7.5 to 15 cm).

Mirrors. A 2002 UK study found that mirrors fitted in stables significantly reduced weaving and head nodding. The authors judged mirrors more effective than many popular remedies, including anti-weave bars. More recently, a small University of California, Davis study of nine Quarter Horses found that a mirror was linked to lower heart rates in the evening.

Food-based enrichment works best between meals. In that same Davis study, a hay feeder ball (a ball with holes for hay to be taken out of that can be moved around on the floor by the horse) produced daily activity patterns closest to those of free-living horses, outperforming a mirror. Effects were strongest at midday and late afternoon, outside routine feed times.

Tracks rather than strips for good doers. A study of 35 ponies in four herds compared strip grazing with a track around the field edge, using the same grazing area. On the track, ponies covered about 7 km a day against 5.3 km on the strip, and showed less aggression. Four weeks per system was too short to show weight differences.

Licks. Earlier studies cited in the thesis found that a lick reduced, but did not stop, crib-biting.

Where enrichment can backfire

Not every well-meant addition helps. Small-mesh nets and overly restrictive slow feeders can frustrate horses, with signs such as tugging at the net, head tossing or pawing. Strip grazing increased squabbling among ponies compared with a track. Putting another horse’s manure or hair in a stable for scent interest carries a disease risk. Persson also notes that studies with negative results are less likely to be published, so the downsides may be under-reported.

Enrichment or basic needs?

The thesis raises an uncomfortable point. Many of the ‘enrichments’ owners shared were really attempts to meet a horse’s basic needs: forage, freedom of movement and contact with other horses. A hay net that holds the normal ration is a feeding method, not enrichment. If a horse needs constant extras to cope with its housing, the housing may be the real problem.

Practical takeaways

• Get the basics right first: ample forage, daily turnout and contact with other horses.
• Favour food-based enrichment, which has the strongest evidence.
• Choose a ground-level slow feeder or larger-mesh net, and watch for signs of frustration.
• Offer enrichment between meals rather than at feed time.
• Consider a shatterproof stable mirror for horses on box rest or stabled alone, especially weavers.
• For good doers, try a track system rather than a strip to encourage more movement.
• Check with your vet which plants are safe before offering branches.
• Watch your own horse. Individual preferences varied across every study.

A note on the evidence

The Swedish work is undergraduate research and has not been peer-reviewed. Its sample, members of an enrichment enthusiast group, is not representative of all owners, and how often methods were mentioned was partly shaped by the group’s themed posts. Most of the studies behind the recommendations above involved small numbers of horses and short trial periods. The clearest finding is how much remains untested.

References

1. Persson, E. (2026). How Swedish horse owners enrich the lives of their horses: an analysis from an ethological and welfare perspective. Bachelor’s thesis, SLU, Uppsala. In Swedish, English abstract. No DOI.
2. Rochais, C., Henry, S. & Hausberger, M. (2018). “Hay-bags” and “slow feeders”: testing their impact on horse behaviour and welfare. Applied Animal Behaviour Science 198, 52 to 59. DOI: 10.1016/j.applanim.2017.09.019
3. Brauns, M., Ali, A., Berger, J. & McLean, A. (2025). Physiological and behavioral responses of stabled horses to three types of environmental enrichment. Animals 15(19), 2779. DOI: 10.3390/ani15192779
4. McAfee, L.M., Mills, D.S. & Cooper, J.J. (2002). The use of mirrors for the control of stereotypic weaving behaviour in the stabled horse. Applied Animal Behaviour Science 78(2 to 4), 159 to 173. DOI: 10.1016/S0168-1591(02)00086-2
5. Kirton, R., Sandford, I., Raffan, E., Hallsworth, S., Burman, O.H.P. & Morgan, R. (2025). The impact of restricted grazing systems on the behaviour and welfare of ponies. Equine Veterinary Journal 57(3), 737 to 744. DOI: 10.1111/evj.14411
6. Amaje, J., Upton, S., Garba, U.M. & Jolayemi, K.O. (2026). The use of hay nets and slow feeders as feeding methods in horse management: a semi-systematic review. Journal of Equine Veterinary Science 157, 105762. DOI: 10.1016/j.jevs.2025.105762
7. Jørgensen, G.H.M., Liestøl, S.H.-O. & Bøe, K.E. (2011). Effects of enrichment items on activity and social interactions in domestic horses. Applied Animal Behaviour Science 129(2 to 4), 100 to 110. Cited via the thesis; DOI not verified.
8. Whisher, L. et al. (2011). Effects of environmental factors on cribbing activity by horses. Applied Animal Behaviour Science 135(1 to 2), 63 to 69. Cited via the thesis; DOI not verified.