Do Hay Pellets Alone Provide Horses Enough Fiber?

Q.  I am considering moving my horse to a new barn for the winter because it has a covered arena. However, the barn managers feed hay pellets instead of long-stem hay, and I’m worried my horse will not get enough fiber. Can hay pellets provide enough fiber?

A. Fiber is a vital component of the forages we feed to horses and is necessary for maintaining a healthy hindgut bacterial population. Often considered “filler” thanks to the way fiber is often portrayed in human nutrition, in the horse fiber  is vital for digestive tract health because it’s a necessary source of nutrients for the hindgut bacterial population.

If you search for the definition of fiber, you’ll find that it is a term used to describe a collection of carbohydrates such as cellulose, pectin, and lignin, which are resistant to enzymatic digestion in the small intestine. Because humans don’t have an extensive population of fiber-utilizing bacteria in our large colons, these carbohydrate fractions aren’t as well digested in our digestive tracts as they are in horses’ gastrointestinal tracts—hence the commonly held belief that fiber is just filler. Even in human nutrition we’re learning about fiber’s role in our large colons, its impact on the bacteria that live there, and the far reaching health consequences it might have.

In the horse—an herbivore, with a large and well-developed capacity for the microbial fermentation of these complex carbohydrates—fiber in the diet is vital. But fiber isn’t a function of a forage’s stem length. Think about commonly used supplemental fiber sources in human nutrition—they are typically powder form and yet can provide a large proportion of a human’s daily fiber need.

Fiber is a measure of these specific carbohydrate fractions that exist in pellets as they do in long-stem hay. So, yes, it is possible to meet a horse’s need for fiber feeding hay pellets.

Not All Hay Pellets are the Same

There are some things to consider, though. Not all pellets are created equally. A pellet that is 100% hay will likely provide enough fiber; however, hay pellets are sometimes mixed with other ingredients such as grains to increase the energy density and improve binding. Depending on the proportion of these other ingredients, the amount of fiber could be reduced to a point where it isn’t adequate.

Check the crude fiber content of the pellets being fed and the ingredient list to determine whether the pellet is mostly hay. Pellets that are mostly hay will have a crude fiber content in the mid- to upper-20% range, possibly higher. Pellets with less fiber can still provide adequate fiber. For example, many complete senior feeds have crude fiber contents that are as low as 18% and can be fed as the sole diet. These typically contain the necessary vitamins and minerals too and some hay pellets also have added essential nutrients. Again, ask to see the analysis so that you know whether you need to be adding other sources of essential nutrients or whether the feed provided will take care of these needs.

It is possible to run into an issue of inadequate fiber if you have to limit intake because your horse gaining too much weight. Pellets are quite digestible due to their small particle size and you might find that the quality of the hay used is actually better than what you have been feeding as hay. This can mean that less total feed is needed to maintain the same body condition, leading to a reduction in fiber intake even though the pellets themselves have a high enough percentage of crude fiber.

Signs a Horse Isn’t Getting Enough Fiber

Horses that aren’t consuming enough fiber will sometimes develop destructive behaviors such as eating shavings, fences, and trees, etc. This is an attempt to increase gut fill or stave off boredom. Pellets don’t take as much chewing as long-stem hay, which can result in more time with nothing to do and potential development of destructive behaviors or stereotypies. Because of the reduced chew time, saliva production and stomach buffering might also be decreased. I recommend using an automated pellet dispenser if feeding large amounts of pelleted feed. These can be programmed to feed small amounts of pellets at predetermined intervals. In this way it is possible to simulate grazing and mitigate some of these potential problems.

Using such a feeder also reduces the risk of choke, which is always a concern when feeding several pounds of pellets in a meal. Feeders exist that dispense only a handful of feed at a time until your predetermined amount is reached. This makes it impossible to gorge on large mouthfuls of pellets.

Take-Home Message

While my personal preference is to feed long-stem hay because it’s closer in form to a horse’s natural diet, it’s possible to maintain a horse on hay pellets and, in some cases, might be preferable. Just make sure you’re feeding the correct type of pellets, your horse is transitioned slowly, and you feed as many small frequent meals as possible.