Equine colic is a common happening in horses world-wide. The severity can range from mild (you might not even notice it) to catastrophic. But there are things that owners and managers can do to help reduce the risk of colic, especially if it is associated with feed and feeding practices.

This is a companion article to 7 Management Tips to Reduce the Risk of Feed-Associated Colic.

These tips  are not exhaustive and need to be adapted to individual circumstances. If you are at all concerned, please contact your veterinarian or nutrition advisor for specific targeted advice.

Equine Colic and Forage

Keep the following tips in mind when you are considering what type and how to feed forage to your horse to help reduce the risk of colic.

If you are feeding preserved forage, ensure that you are feeding sufficient amounts. Most importantly, make sure that your horse is actually eating enough. (See 10 Tips for Feeding Forage to Horses.)

Suitable Forages

All forages should be suitable for feeding to horses. Below are some tips and examples.

Haylages and silages have a higher water, lower dry matter, and therefore lower fibre content weight for weight than hay. Therefore, intakes need to be adjusted appropriately. It is advisable to get specialist nutrition advice before feeding silages and nutritionists typically recommend not using very low pH silages.

Avoid feeding fine grass cuttings to horses. Issues might be related to their nutrient content, their effects on chewing, and the potential to be contaminated with oil from the cutter.

The grass, herb, and plant species used to make your hay need to be suitable for preserving and feeding to horses. This might be of increasing importance with the increasing use of more bio-diverse pastures for grazing and hay making.

Use Quality Forages to Avoid Equine Colic

All forage fed should be of a high hygienic quality. Hay should not contain moulds. Never feed mouldy hay to horses.

You should check for visual contaminants in the hay. These can include weeds or foreign bodies (e.g., baler twine fragments, rodent or bird droppings, dead animals, etc.).

Store Feed Appropriately

Always store feed and forage appropriately. Do not feed mouldy feed or forage.

With respect to haylage: When fungi can be seen on the surface of any part, the risk is that the whole bale will be affected even if you cannot see that it might be.

Types of Hay/Straw

In general, try to  avoid very mature hays/straw, especially in certain breeds and animals prone to impaction colic. Note that donkeys can do very well on a predominantly straw-based ration.

If you do need to add in straw to help reduce calorie intake, then introduce very gradually and ensure it is of good hygienic quality.

The author recommends limiting straw to a maximum of 30%-50% of the diet without professional advice. However, donkeys and mules often do well on up to 100% straw as their forage source.

Tips and Cautions when Reducing Forage Intake

If you have to restrict forage intake (e.g., for weight control reasons), try some of the following tips.

  • Try using small-holed nets, double haynets, chopped forages (chaff), or even using high-quality hay blocks to increase the amount of time it takes for a horse to eat a forage ration. (Note that if you restrict forage intake but stable the horse on straw or shavings, the animal might ingest significant amounts of bedding. This might not cause significant problems for some individuals, but could increase the risk of colic in others.)
  • Be aware that when restricting forage intake but providing preserved forage in areas with high sand presence, there could be an increased risk of sand colic.
  • For some horses with particular types of colic (e.g., epiploic entrapment, colon impactions and displacements, enterolithiasis), consistent access to pasture appears to be particularly advantageous. For some conditions, however, it might be a risk factor (e.g., duodenitis-proximal jejunitis and sand colic). (Author’s note: Regular checking, and being aware of your horse’s normal patterns of behavior, is obviously essential if maintaining 24/7 out at pasture.)
  • If you have a horse that is prone to enterolith formation or you are in an area where this is commonly found, consider reducing the amount of alfalfa hay fed and provide oat/grass hays instead. Contact your veterinarian or nutritional advisor if concerned.

Feeding Cereals and Complementary Feeds

To help reduce the risk of equine colic, reduce the amount of starch fed in each meal. Based on various studies, including work on gastric ulcers, the author’s current advice is to try to reduce the intake of starch and sugar (i.e., non-structural carbohydrates or NSC) ideally to <1 g/kg body weight per meal for all horses. This is equivalent to a 500g (1.1 pounds) per meal for a 500kg (1,100 pound) horse.

For older horses, even if they are not prone to laminitis, about half this might be beneficial (<0.5g/kgBW/meal). Note that even less might be required if the animal is insulin dysregulated. Monitoring pre- and post-feeding insulin might be helpful. (See Feeding Horses and Ponies Prone to Laminitis Part 1 and Part 2.)

Feed no more than 2 kg (4.4 pounds) of feed per meal for horses 500 kg (1,100 pounds) and over. Feed less for ponies.

Every-Hungry Horse

If your horse seems to require ever-increasing amounts of feed in order to maintain condition and energy—and there is no suspicion of ill health—consider:

  • Increasing the number of meals (whilst keeping down the size of each meal).
  • Changing to a feed with a higher energy content.
  • Gradually adding in non–rancid vegetable oil (up to 1ml/kg of bodyweight/day in divided servings).
    • When feeding significant quantities of oil, obtain nutritional advice to check the balance of the overall ration. This is particularly important for vitamin E and calcium intake. Palatability can be very individual. Keep the vegetable oil ideally in a fridge or very cool conditions between adding to the feeds.
  • Ensure any cereals fed (other than oats) are cooked (e.g., steam flaked or micronized) to improve digestibility. (Note that cereal-rich feeds are not always suitable for an older horse, especially if it is retired or not in significant work, or if it has PPID, insulin dysregulation, or is prone to laminitis.)

Further Reading

  • Patricia A. Harris, MA, PhD, VetMB, DipECVCN, MRCVS
    Pat Harris, MA, PhD, VetMB, DipECVCN, MRCVS, EBVS European specialist in veterinary and comparative nutrition, as Director of Science for Mars Horsecare and Head of the WALTHAM™ Equine Studies Group is responsible for their equine research conducted in collaboration with experts at institutes and universities globally. This provides the science behind the SPILLERS™, BUCKEYE™ Nutrition and WINERGY™ brands. She is also a scientific advisor to MARS Equestrian™ sponsorship. She is an RCVS specialist in Veterinary Clinical Nutrition (equine) and a past president of the British Equine Veterinary Association.
    View all posts