10 Tips for Feeding Forage to Horses

Forage is the foundation of the equid diet. This is the first in a series of articles that can help you learn more about forages. Plus we’ll give you 10 key takeways about feeding forages to your animals!

Forage Definitions

Let’s start with defining what we are talking about when we say forages.

Forage refers to the whole plant (except roots). Forages include:

Cool (e.g., Timothy) and warm (e.g., Teff) season grasses (which also include the various cereal plants) and legumes (e.g., alfalfa). Forages can be fed fresh (e.g., grass pasture) or preserved (e.g., hay, haylage, silage).
Other forages that are ingested by equids include non-leguminous ‘weeds.’ For example those might be dandelions and herbs within pastures plus browse species (see below).
Browse species—such as heather or gorse—can constitute a significant proportion of intake by native wild ponies, especially during winter. These can also be a large portion of forage intake for domesticated animals that forage in hedgerows or those in tropical countries that might rely to some extent on ‘cut and carry’ browse (when someone cuts fresh forage from another location and brings it to the animal).

Roughage is a high-fiber feedstuff generally obtained as a crop residue or by-product (e.g., straw, cereal hulls, beet pulp). Typically, roughages are used interchangeably with the term forage. These feedstuffs should be included when considering total forage intake.

The term ‘foraging’ is used to encompass all feed intake activities of horses on pasture and when housed.

10 Key Take-Home Messages on Feeding Horses Forages/Fibre

Perhaps surprisingly, inappropriate forage provision is one of the key limitations in many horse diets. These 10 tips can help to reduce the risk of forage limitations in your horse’s diet.

1. Forage as the Foundation

Good, hygienic, quality, long-stem forage (grass, hay, or haylage) should ideally be the foundation of most equine diets. An exception is for animals with dental issues (see Tip #3 below). Many horses or ponies can be fed on a forage-only diet if you include the proper ration balancer. This is true even for many horses in work. This is, of course, if the appropriate forage is fed.

Horses are basically non-ruminant herbivores. This means that they are suited to eating high-fiber diets due to continual microbial fermentation mainly within their hind gut (caecum and colon). Forage provides fiber to the horse.

Horses require sufficient fiber in their diets. This not only provides some nutrients/energy, but satisfies their need to chew and supports their gut health.

2. Match the Forage to the Horse

Use these points to help you feed the correct forage:

The forage type and maturity (therefore, nutrient plus energy content) should be matched to the needs of the individual horse.
The same forage might not be suitable for all horses. It worth being aware of what forages are available in your area.
The nutrient and energy that forage provides will vary considerably depending on the type of grass and the stage of maturity when it was cut. Overweight animals, for example, are often better suited to forage that is more mature so that it provides fewer calories. Donkeys can often be fed diets based on good, hygienic, quality straw, but such diets will not provide enough energy and might cause colic in certain horse/pony breeds/individuals. Analysis of your forage can be important; discuss this with your nutritional advisor.
The amount of fiber provided per pound/kg of forage as you feed it will also vary depending on its moisture content. An example of why this can be important is the potential for underfeeding haylage (and therefore structural fibre) when changing from hay. This is because feeding on an “as fed weight basis” does not account for the higher moisture typically present in haylage. The actual water content in haylage can be highly variable—from 20% to 50%. This needs to be taken into account in any feeding plan (see Table A). Again, analysis of your forage is important. Discuss this with your nutritional advisor.
Although the water-soluble carbohydrate (WSC) or ‘sugar’ content of warm season grasses tends to be lower than that of cool season grasses, this will depend on many factors. Those include the type of grass, the time of year, environmental conditions, its maturity, and how it was conserved (haylage, for example, does not necessarily have a low WSC content). Similarly, more mature cool season grasses/hay tend to have a lower WSC content than younger, less mature grasses/hay. However, this can be very variable. If the WSC content is a key consideration in your horse’s diet, it will be important to analyse your hay/haylage and/or monitor your horses’ insulin response to that forage. Discussing these issues with your veterinarian/nutrition advisor can be very helpful.
It is important to discuss with your veterinarian or nutrition advisor about specific nutrient or other considerations (including regulatory considerations if competing) linked with the forage type you are feeding.

3. Dental Considerations

As horses age, they might have issues chewing mature hay and will prefer softer, less-mature forages. However, this can be an issue if they are overweight or require low NSC in their forages. Alternative forage types might need to be considered.

For those animals that have problems chewing long-stem forage, alternatives can include short-chopped fiber (chaff) and soaked fiber-rich mashes (see Tips on Feeding Older Horses with Dental Issues and A Guide to Feeding Mashes).

4. Feed Enough, But Not Too Much

Horses at a healthy weight (i.e., not overweight or underweight) should ideally be fed forage/roughage at around 2% of their bodyweight as dry matter.¹ This should be fed so that forage is regularly available but not fed in excess (to minimize time between meals and to avoid wastage).

The amount of forage that needs to be fed to maintain a healthy weight obviously will vary according to the individual animal, its energy requirements, the calorie content of the forage, and what else it is being fed. Equines at a healthy weight (i.e., not overweight) should ideally be eating at least 1.5% of their bodyweight in dry matter (DM) per day as forage/roughage.

Ideally at least 1% of their body weight in dry matter should be as long fiber (taking into account dental considerations). Hays should be at least 85% dry matter.
So, if we take a horse being fed just hay, and we take a typical hay at 90% dry matter, it means the horse should be fed 1.5/0.9% (i.e., at least 1.7%) of its body weight of hay as fed (i.e., 1.7% x 500/100 = about 8.3 kg or 18.3 pounds, which rounded up means approximately 8.5 kg or 18.5 pounds of hay for a 500 kg (1,100 pound) horse not getting any other forage or fiber sources (fresh or preserved). (See Table A.)
Even equines in very high-intensity work should be fed at least 1.25% of bodyweight (e.g., 6.25 kg or 13.8 pounds DM for a 500 kg or 1,100 pound horse) in DM as forage/roughage.
For animals on weight-restriction diets, reducing below these intake levels with no other feed provision other than a blancer will require discussions with your veterinarian and/or nutritionist. Very close veterinary supervision is recommended in those cases.
Soaking hays reduces their dry matter content. This needs to be taken into account when developing a ration for horses on a restricted diet that includes soaked hay. We typically suggest you allow for a 20% loss in DM with soaking.

5. The Timing of Feeding is Important

Don’t wait too long between forage meals. This increases the risk of gastric ulcers as well as potentially the development of certain undesirable behaviours.

Even when restricting forage intake to promote weight loss or prevent weight gain, remember to ensure—especially during typical daylight hours—that ideally there is not more than 4-5 hours between forage provision.

When restricting forage intake, consider how you can best extend the time your horse spends foraging using hay boxes, small-holed haynets, etc.

6. Consider Alternative Fibres and Energy Sources

If additional energy provision is required, before reaching for cereals/grain or cereal/grain-based feeds consider changing to a more calorie/energy-rich forage. You also might use complementary feeds based on highly digestible fibres that if necessary are high in oil. Or you could consider gradually introducing fresh/non-rancid vegetable oil/fat to the existing ration. Always check the resulting diet to ensure the necessary nutrients are being supplied in the proper amounts. This is especially important for vitamin E and calcium.

7. Balancers Can be Key

It is unlikely that feeding forage (fresh or preserved) alone will meet optimal nutrient needs, especially at certain life stages or work intensities. Most, if not all, forage-based rations will need to be fed alongside an appropriate balancer if you are not feeding the recommended amount of a fortified feed.

Remember:

For those animals that are prone to laminitis and/or are insulin dysregulated, choose a low-starch and -sugar (i.e., NSC) providing balancer. Depending on its NSC content, you ight need to profide it in two or three meals.
A balancer is especially important if feeding soaked or preserved forage and/or for those animals on a restricted forage diet. If you are feeding less than the recommended amount of a fortified feed for your horse’s age and workload, then you might need to feed a reduced amount of balancer in addition to your current feed. For example, if you are feeding half of the recommended amount of fortified feed, then consider adding in half the recommended amount of an appropriate balancer in order to provide a balanced diet (exact ratios obviously depend on the nutrient content of your fortified feed and balancer; this is just an approximate guide).
The balancer should complement the type of forage you are feeding (e.g., different balancers are needed depending on whether your diet is alfalfa rich or meadow grass rich).

8. Change Over Slowly

To help reduce the risk of colic or other gut issues, it is very important to make changes in the forage slowly.

Small changes should be made gradually over 3-5 days. However, a 2-week (and possibly more than 3-week) adaptation period might be required, especially if the nutrient composition (energy source, protein level, water soluble carbohydrates [WSC]) is unknown or is known to differ considerably between the forage you are changing to and from.
Moving from pasture to a stabled environment also influences normal gut movements (i.e., gut motility), potentially increasing the risk of gut problems. So, if possible, also do this gradually.
When it is not possible to make changes gradually (e.g., need for sudden box rest), monitor your horse even more carefully for signs of a problem for the next couple of weeks.

9. Store Appropriately

Like your complementary feeds, forage should ideally be stored in cool, dry conditions. Depending on the type of forage you are feeding, additional considerations might be required.

It is essential, for example, that haylage bales are stored appropriately to minimize the risk of damage from mammals and birds to the outer protective wrap (that prevents air access). This might necessitate storage away from hedgerows, the use of protective netting over the bales, and even surrounding them with a low electric fence (e.g., strands 1-3 feet from the ground).

10. Hygienic Quality

All forage provided to horses should be of good hygienic quality. Forage that looks or smells mouldy obviously should not be fed. Check also for the presence of contaminants such as sand/soil, noxious plants, weeds, and various poisonous plants.

Unfortunately, some moulds, etc., cannot be seen. So, if you are concerned, discuss options for testing with your veterinarian/nutritionist. This is particularly important to consider if your horse is coughing, failing to perform or thrive, or if digestive disturbances are present (such as recurrent colic, gastric ulcers, or abnormal droppings/manure).

Some Final Points

Remember that hay that has a dry matter less than 85% (i.e., contains more than 15% water) might not have been dried sufficiently and could be at higher risk of becoming mouldy.
Whilst horses are unlikely to eat certain plants when fresh (unless they have no other option), they will when included in preserved forages (e.g., ragwort in hay or haylage).
Sycamore shoots can still be toxic when cut and dried within hay, so clear those before making hay.
If the outer wrapping of a haylage bale has been damaged and visible mould can be seen, it is likely that spoilage will have occurred throughout the whole bale even if there is no obvious mould in areas away from the breach.
Soaking hay increases the bacterial count. Consider limiting the length of time of soaking to 30 minutes if aiming to reduce ‘dust’ and 1-3 hours in hot weather if soaking to reduce WSC. Don’t forget that the soaking fluid should treated as effluent and appropriately disposed of. Feed soaked hay as soon as possible.
If using steamers to reduce the mould load of your forage, you need to ensure that the correct temperature has been reached throughout the whole bale.

Finally, some senior horses are still being used in competition. Therefore, the risks of feeding certain forages or forages contaminated with substances against the rules of competition/racing need to be considered. If you are competing under rules, always source forage from a reliable provider and check with your veterinarian/nutritionist if there are any specific risks you should consider.

Table A indicates how you can calculate the recommended minimum and target amounts of preserved forage for your horse to help support its health and wellbeing.¹ Please note that to avoid weight gain even on these minimal amounts, for some individuals it might be necessary to adjust the hay that is given to one with a lower energy content.

To determine your horse’s recommended forage needs, use the following calculation:

Take the weight of your horse in kg and divide by a 100 (or if in pounds by 220) = A
Times by the amount of drymatter that is recommended as a minimum (1.5) or target (2) = A x 1.5 or 2 = B
Divide B by your preserved forages Dry matter percentage and times by 100 = (B/DM%) x 100 gives
a guide to how much of your preserved forage you need to meet this recommended level.

		Pony 250 kg/550 lb	Pony 250 kg/ 550 lb	Horse 500 kg/ 1,100 lb	Horse 500 kg/ 1,100 lb
		Recommended Minimum	Target	Recommended Minimum	Target
		1.5 kg/3.3 lb DM per 100 kg/220 lb BW (1.5%)	2 kg/4.4 lb DM per 100 kg/220 lb BW (2%)	1.5 kg/3.3 lb DM per 100 kg/220 lb BW (1.5%)	2 kg/4.4 lb DM per 100 kg/220 lb BW (2%)
		DRY MATTER INTAKE PER DAY (kg/lb)
		3.75 kg/8.25 lb	5.0 kg/11 lb	7.5 kg/16.5 lb	10 kg/22 lb
Forage type	Typical Dry Matter	INDICATED AMOUNT ON AN AS FED (i.e. Fresh) BASIS PER DAY (kg/lb)
Hay	90*	4.2 kg/9.2 lb	5.6 kg/12.2 lb	8.3 kg/18.3 lb	11 kg/24.4 lb
Haylage (dry)	70	5.4 kg/11.8 lb	7.1 kg/15.7 lb	10.7 kg/23.6 lb	14.3 kg/31.4 lb
Haylage (wet)	50	7.5 kg/16.5 lb	10 kg/22 lb	15 kg/33 lb	20 kg/44 lb

* Note that if your hay has a lower DM, then more hay will need to be fed (e.g., for hay with the minimally recommended DM), then about 9 and 12 kgs of fresh hay would be required.

Reference

Review of feeding conserved forage to horses: recent advances and recommendations. 2017. P.A. Harris, A.D. Ellis, M.J. Fradinho, A. Jansson, V. Julliand, N. Luthersson, A.S. Santos, and I. Vervuert. Animal 11:6 p 958-967.