Skip to content
Search Library
thumbnail

Most horses skim calories from forages of varying quality, maximizing caloric intake from every morsel, so much so that grazing muzzles and drylots are sometimes needed for curbing insatiable appetites and maintaining appropriate body condition scores. When extra energy is needed, cereal grains such as oats, corn, or barley frequently serve as the first sources of supplemental calories. Recent research suggests* that soluble fiber also provides adequate energy for exercising horses and could be a healthy alternative for horses at risk for colic.

Forages are the backbone of any horse’s diet. The cellulose fiber in grass and legumes is broken down by the microbes—the horse biome—in the cecum and large intestine. These microbial organisms produce energy in the form of volatile fatty acids (VFAs), such as acetic, propionic, and butyric acid.

“VFAs are a primary energy source for horses. They can also use glucose as an energy source from digestion of starches found in cereal grains; however, excess dietary starches can cause problems in susceptible horses, just like in humans,” explained Crandell.

To further explore whether soluble fiber—such as the pectic found in beet pulp, citrus pulp, and soy hulls—affected the overall health of horses and provided enough energy for work, researchers collected cecal and fecal samples from Norwegian Coldblooded Trotter horses to measure VFA production. Blood samples were also obtained for assessing glucose and insulin, the hormone responsible for regulating blood sugar levels.

Separate diets were offered to horses, with and without cereals (oats and barley):

  • Timothy hay;
  • Timothy hay and molassed sugar beet pulp fed with either oats or barley, collectively referred to as the cereal grain diets; and
  • Timothy hay plus a loose chaff-based concentrate (chopped hay, apple pumice, and beet pulp) high in soluble fiber.

Researchers uncovered two key findings: (1) diets with soluble fiber result in stable and constant plasma glycemic and insulinemic responses, and (2) diets with a high content of soluble fiber provide enough energy for coldblood-type horses at moderate work.

“These results suggest that a forage-based diet with high level of soluble fiber is metabolically beneficial and capable of providing sufficient energy for some types of active horses,” Crandell concluded. “However, this was a very short study and further research is needed to see the long-term effect of maintaining a horse in moderate to heavy work on a forage-only diet.”

*Brøkner, C., D. Austbø, J.A. Næsset, et al. 2016. Metabolic response to dietary fibre composition in horses. Animal. 12:1-9.

X

Subscribe to Equinews and get the latest equine nutrition and health news delivered to your inbox. Sign up for free now!