Nutrition

Hemp Shows Promise as Fiber Source

By Adam Marcus

Ground hemp appears to be a promising option as a fiber additive to horse feed, according to researchers who used an in vitro analysis to assess the digestive properties of the plant material.

The 2018 Farm Bill legalized the production of Cannabis sativa, commonly known as hemp and marijuana. The difference between the 2 products involves the amount of tetrahydrocannibinol (THC), which gives pot its kick, in each. The 2018 law permits sale of hemp and products derived from the plant if they contain no more than 0.3% THC, considered too low to produce psychoactive effects.

Hemp is hardy and easy to grow, so the new law could be a boon for stables looking for an alternative to conventional sources of fiber.

“Hempseed meal is considered more of a multifaceted feed ingredient due to its diverse nutrient composition–high fat, high fiber, high crude protein, low in nonstructural carbohydrates,” said Ryon Springer, MS, a research coordinator at Kentucky Equine Research-South, in Ocala, Fla., who led the latest study.

Mr. Springer and his colleagues used fecal material from 4 geldings to examine the in vitro true digestibility of various horse feeds: hempseed (with <0.01% THC), alfalfa hay, Coastal Bermuda-grass hay, soybean meal, rice bran pellets, and a commercially available pellet concentrate (Equiline Pellets, Bluebonnet).

“The current in vitro methods, specifically for horses, do not exactly match in vivo digestibility of feedstuffs,” Mr. Springer said. “Generally, we use the in vitro digestibility measures as a method of comparison and typically the feedstuffs are ranked in the same order when used in vivo or in vitro; however, there is research in the works to better modify in vitro methods to better represent” what happens in the animal gut.

Hempseed had a high content of pre-fermentation neutral detergent fiber–a measure of the fibrous matter in a sample of plant material—falling above alfalfa, rice bran, and soybean, but below the grass. Its performance against the commercial pellets was mixed but in some cases was higher.

“The mixed effects when comparing to the commercial concentrate likely had to do with the quality of the fiber of the concentrate,” Mr. Springer said. “As this was not a single-source feedstuff, we do not know the exact formulation that could contribute to the mixed statistical differences.”

Hempseed had a greater in vitro true digestibility than Coastal Bermudagrass, but was less digestible than the other feed products, according to the researchers, suggesting it has potential as a good source of fiber for horses.

For the moment, hempseed isn’t approved for use in horses in the United States, and he doesn’t recommend feeding the substance to animals until the government and feed officials give the okay.

“As with other alternative feed ingredients, hempseed will likely be used to help reduce the use of more common ingredients, and likely won’t be a single-ingredient product fed to horses,” he added. MeV

To learn more about the 2018 Farm Bill, visit: https://www.brookings.edu/articles/the-farm-bill-hemp-and-cbd-explainer/

For more information:
Springer RW, et al. Fiber composition, in vitro true digestibility, and fiber degradation of hempseed meal compared to mainstream feedstuffs using equine feces as microbial inoculum within the DaisyII Incubator.
J Equine Vet Sci. 2025;144:105230.
https://www.sciencedirect.com/science/article/abs/pii/S0737080624002363?via%3Dihub