Horses can satisfy virtually all their nutritional requirements from forage. It is the most important part of any feeding regime and should always form the base of any ration. Ideally, horses should be eating forage for some 16–24 hours a day.
When horses chew, saliva production is stimulated. Chewing forage takes much longer than chewing cereal-based feeds so more saliva is generated, acting as a buffer to acidity in the horse’s stomach. Without it, excess acid can lead to the development of gastric ulcers, which are painful and can cause losses in weight, condition and even performance.
Traditionally, horses spent longer periods of time foraging in order to get the nutrients they required. As such, horses have a high ‘physiological’ desire to search out food and chew. If this natural behavioural drive is not met, it can lead to undesirable behaviours, such as wood chewing or oral stereotypies (previously called vices) like crib-biting and wind-sucking. In addition, there is increasing evidence to suggest that horses fed on a diet that is high in fibre and low in starch are less fractious and excitable.
Amount & type of forage
Forage can take the form of fresh grass, or conserved forage, such as hay, haylage, straw (in moderation), alfalfa or dehydrated grass. The amount and type of ideal forage to feed will largely depend upon the horse in question, however, as a rule all horses should receive at least 1% of their bodyweight per day as forage (to safeguard correct digestive function).
Choosing a forage diet
Most horses can derive all their energy requirements from a forage-based diet (depending upon their age and workload). However, the energy value of forage depends upon:-
- Digestibility (stage of growth at which the forage source was cut)
- Species of grass (for hay/haylage)
- Water-soluble carbohydrate content (sugars)
Therefore, for the average working horse (light workload), a sufficient forage-based ration would consist of a good quality hay or haylage (7–9 MJ/ kg), supplemented with a good quality chaff (alfalfa-based) and potentially some beet pulp (10–13 MJ/kg), if extra energy is required.
Vitamin and mineral supplementation
It is worth noting, however, that horses fed a forage-only diet or one where the hard feed element is fed at a lower quantity than the manufacturer’s stated guidelines, are likely to need additional vitamin and mineral supplementation.
In summary, the equine digestive system has evolved to be constantly processing fibre rather than large cereal meals. If insufficient forage is provided, it can disrupt the health of the gastro-intestinal tract leading to conditions such as acidosis and colic. Ideally, all horses should have access to forage at all times.