Equine diets: Slow Feeding

Slow down! A look at slow feeding and feeders.
by Kerri-Jo Stewart, BPE, MSc as published in Equine Wellness, Vol 7, issue 3; May/Jun 2012

Although free feeding is considered best for horses, it is not always beneficial (or easy to do) in captive situations. Many people feed their horses three times a day, including hay, complete feed and/or grain. Although some horses eat slowly and others only eat what they need, many will eat their portions quickly and continuously until they are gone. Then they have to wait for the next feeding.

Forage, naturally One problem is that we feed hay, which is concentrated grass, or have lush pastures, and our horses don't have to move around much to obtain their food. In the wild, a horse may eat for 16 to 20 hours a day, grazing on sparse natural pasture, and travel an average of 12 miles in order to find adequate food. The purpose of slow feeders is to try to feed horses at a similar rate to wild foraging. Slow feeding is called "restricted feeding" versus "free feeding". Feed intake is limited by speed, not quantity. Horses can only take small bites, but the food is available at all times. In general, since the horse is meant to have a constant supply of small quantities of food travelling through the gut, the idea of slow feeding makes sense.

Touring the digestive tract The equine stomach holds around four gallons. This is actually a small size for such a large animal and limits the amount of food a horse can eat at one time. There is a continuous production of acid in the stomach, and chewing creates saliva, which provides a protective coating. It is thought that without a continuous supply of saliva, stomach ulcers can become common. The food then goes into the foregut or small intestine, which is 50’ to 70’ long and holds around 10 to 12 gallons of food and water. Almost all the protein digestion is done here, as well as around 50% to 70% of simple carbohydrate digestion. The nutrients are absorbed into the bloodstream. The primary mode of digestion here is enzymatic -- enzymes break down proteins and carbohydrates, making them available for absorption. Food and water travel though the foregut in a matter of hours. The hindgut of the horse is where digestion occurs, primarily through microbial fermentation. The first part of this system is the cecum, which is a sack about 4’ long and holds around seven to eight gallons. Then things move along to the large colon, which is around 10’ to 12’ long and holds up to 20 gallons. This is where fiber is broken down by fermentation into nutrients the horse can absorb. Impaction colic can occur here, especially when food isn't constantly available. The opposite problem of having too much food available at once also creates dramatic problems in the hindgut. Large grain meals cause a hindgut acidosis as the microbes increase the rate of fermentation. The increased acidity can damage the cellular walls and result in a leakage into the bloodstream. The small colon is about 10’ to 12’ long and can contain around five gallons of now digested food and fluids. For the hindgut to work properly and remain intact (untwisted or un-kinked), the gut needs a constant supply of fiber and water. This will keep fermentation going consistently, effectively keeping the hindgut weighted and healthy and, as a result, preventing conditions that can contribute to colic.

Selecting or creating your slow feeder There are numerous types of slow feeders being used and developed, and many people are creating their own as well. The basic idea is to make the horse work to get the food and thus not permit large mouthfuls of food. Small mesh nets are made so that horses can eat naturally close to the ground (preventing certain respiratory problems that can occur when horses eat with their heads elevated). The mesh needs to be small enough so the horses can't get caught up on the nets. People use all kinds of netting, including hockey nets or commercially available purpose-made netting arrangements. There are also hard grates as well as mobile hard feeders made specifically for dispensing either grain or hay. A hard mesh is placed over the hay, making the horse work at getting the feed so he is only able to eat small mouthfuls. There are even grain dispensers shaped like balls that only dispense food a couple of pellets at a time as the horse moves it around. Ensure the feeder is safe, particularly if you create your own. Some people have reported their horses getting wounds on their noses from specific types of nets. Nets may also not be practical for shod horses. Others have noted that some types of metal gridding can cause damage to horses’ teeth. Also, ensure that any feeders are not able to splinter or break. Do your research before buying or constructing the right slow feeder for your horse’s needs, then monitor him with the feeder to ensure it is safe. In the wild a horse may eat for 16 to 20 hours a day, grazing on sparse natural pasture, and travel an average of 12 miles in order to find adequate food. Large grain meals cause a hindgut acidosis as the microbes increase the rate of fermentation. The increased acidity can damage the cellular walls and result in a leakage into the blood stream.