Horses are hard-wired to eat and are referred to as "trickle grazers". Free-ranging horses will graze or forage for around 10-15 hours per day (some up to 18 hours) with foraging behaviour spread over 10-15 individual feed bouts. Between these bouts horses may participate in other non-foraging activities such as rest/sleep, play, travel, grooming, drinking. It is rare for individual bouts of non-foraging activities to naturally exceed 3 hours in duration.
When maintained in stables or in confinement horses will still spend 8.5-12 hours per day on foraging-related behaviours. This time will include the time spent consuming their hard feeds and hay allocations but many research studies examining dietary intake behaviours of horses during day and night have found that stabled horses will compensate their hard-wired need to forage by consuming bedding (eg. shavings) and manure, or may participate in increased water play, drinking, or display increased movement or "mouthiness". One study observing overnight intake behaviours found that when the horses were presented with their hay nets at 5pm they generally finished the contents of their allocated hay nets (average quantity 6kgs hay) by about 1am. As the morning hay was not provided until 7am this meant the horses had up to 6 hours to perform other non-foraging and foraging behaviours. As horses only sleep for 2-3 hours per night, several horses in this study compensated their foraging behaviour by eating their bedding and manure.
Further, it is understood that some horses on restricted forage diets may go on to develop oral stereotypical behaviours such as wood-chewing or crib-biting. Indeed a study exploring dietary intake and behaviours of 2900 race horses revealed that race horses fed less than 6.8kg per day of forage showed an increase in abnormal behaviours (eg. oral stereotypical behaviours, weaving).
So, how can we help maintain our horse's mental health in a good state?
Well, when it comes to forage, size and presentation matters. Ideally, horses maintained in stables or confined spaces should have ad lib access to long chop forage (hay/haylage). If this is not possible then here are few things to consider:
As a minimum, horses and ponies should receive no less than 1.5% of their body weight in forage (calculated as dry matter) per day in addition to any hard feeds. For a 500kg horse, with no access to pasture, this equates to approximately 9kg hay (80% dry matter) per day.
Long chop hay takes twice as long as short chop chaff to eat (and produces more saliva which is necessary for a healthy gastrointestinal tract).
The recommended length for chaff is greater than 2.5cm and adding chaff (~2.5 - 4cm in length) to pelleted concentrates lengthens the consumption time.
Presenting hay in small holed hay nets increases the consumption time compared to hay presented in large holed hay nets or no hay net.
Where possible, spread feed times out through the day to prevent long periods (>4-5 hours) without foraging opportunities.
To find out more about Manuka Chaff Pty Ltd hay and feed products contact David Wallis at firstname.lastname@example.org
Ellis, A.D., Fell, M., Luck, K., Gill, L., et al. (2015) Effect of forage presentation on feed intake behaviour in stabled horses. Applied Animal Behaviour Science 165: pp.8894.
Ellis, A. D., Visser, C. K., Van Reenen, C.G. (2006) The effect of a high fibre versus low fibre diet on behaviour and welfare in horses, Proceedings of the 40th International Congress of the ISAE, University of Bristol, p. 42, Cranfield University Press, Abstract
Ellis, A. D., Redgate, S., Zirchenko, S., Barfoot, C. and Harris P. (2014) The effect of presenting multi-layered forage on night-time budgets of stabled horses, In Proceedings of the European Workshop on Equine Nutrition, Leipzig University, pp.98-100
Harris, P.A., Ellis, A.D., Fradinho, M.J., Jansson, A., et al. (2017) Review: Feeding conserved forage to horses: recent advances and recommendations. Animal 11(6): pp.958-967.
Manuka Lucerne haylage is a type of conserved forage. Instead of leaving the harvest to dry before baling, as would be done for hay