Alternative Fiber Sources for Horses

Much of the country is experiencing drier than normal conditions this summer, so some horses living on pasture might soon have limited forage choices. With decreased forage growth also comes a decrease in hay production. Therefore, owners might want to familiarize themselves with alternative fiber sources that could be used to supplement their horses' diets if hay becomes scarce in the near future.
No matter the breed or intended use, all horses require fiber in their diets. According to the National Research Council's Nutrient Requirements of Horses (2007, 6th Edition), a large body of evidence suggests that insufficient dietary fiber can lead to several digestive issues (such as colic) and behavioral vices (such as cribbing) in horses. Horses' fiber needs are met most commonly by pasture and hay, but in the absence of these sources, horse owners must find alternative fiber options. Some common alternatives include hay cubes, complete feeds, and fiber byproducts.
Hay cubes are an excellent fiber source for horses, and are generally easily accessible at most feed stores. The two main benefits to using hay cubes versus hay are:

• Hay cubes typically contain less dust than hay, meaning horses are less subject to inhaling particles that could contribute to respiratory disease; and
• Offering hay cubes generally results in less wasted feed compared to hay.

If offered voluntarily, most horses will consume more hay cubes than hay, so owners should measure and monitor their horses' intake. Hay cubes can be fed just like hay, at a 1:1 ratio of the like hay type the horse currently consumes. For example, if a horse consumes five pounds of timothy hay at each feeding, replace that with five pounds of timothy hay cubes and adjust if needed to maintain the animal's proper weight. Hay cubes are heavier in weight, so you'll need to weigh them to ensure the horse is getting the proper amount of forage.
Complete feeds are formulated to provide a large proportion of a horse's nutrient needs, including fiber, and are readily available through most equine feed manufacturers. Complete feeds usually contains more than 16% crude fiber and are designed to be fed in larger amounts compared to a lower fiber grain mix with little to no hay alongside. Thus, provide several small meals throughout the day. Feeding directions are included on all complete feed packages; following label directions is important to ensure horses consume adequate amounts of nutrients, fiber, and other feed components.
Byproduct fiber sources include beet pulp, bran, and grain hulls. Beet pulp, produced by sugar beet processing, is a popular fiber source for horses because of its digestibility and palatability. Studies have shown that a horse's diet can contain up to 55% beet pulp without negative effects. It's important to remember, however, that beet pulp's digestibility is higher than most grass hays, so ensure the horse's diet is balanced properly when making the switch.
Brans, such as rice bran and wheat bran, are another option but are often less desirable due to their high phosphorus concentrations. If feeding bran, ensure the horse is consuming adequate calcium to keep the calcium:phosphorus ration to at least 1:1. Additionally, remember that rice bran contains high fat levels, so it should not be used in overweight or obese horses.
Oat hulls are also high-fiber, but are often dusty and should be blended with water prior to feeding.
Because these fiber byproducts are only fermentable fiber sources, they should be fed alongside hay or another complete fiber source. Thus, these sources should be used to stretch hay rather than replace it.
Take-Home Message
Horse owners should familiarize themselves with alternative fiber sources to either stretch or replace pasture and/or hay that could become scarce as fall and winter approach. Hay cubes, complete feeds, and byproducts are all viable fiber sources and can be beneficial when fed correctly. If questions arise on feeding alternative forage sources to individual horses, contact your veterinarian or equine nutritionist.

About the Author

Kristen M. Janicki, MS, PAS

Kristen M. Janicki, a lifelong horsewoman, was born and raised in the suburbs of Chicago. She received her Bachelor of Science degree in Animal Sciences from the attend the University of Illinois at Urbana-Champaign and later attended graduate school at the University of Kentucky, studying under Dr. Laurie Lawrence in the area of Equine Nutrition. Kristen began her current position as a performance horse nutritionist for Mars Horsecare, US, Inc., and Buckeye Nutrition, in 2010. Her job entails evaluating and improving the performance of the sport horse through proper nutrition.