Understand and Maximize Fiber Fermentation in Horses

Gastrointestinal health of any horse depends closely on the efficiency of fiber fermentation in the hindgut, as increased exposure to microbes bolsters feed degradation and energy production. Despite an abundance of knowledge about the hindgut, actually monitoring the passage of feed through the cecum and colon poses numerous challenges for researchers.

“A major roadblock in measuring the retention time of ingesta in each segment of the gastrointestinal tract is our lack of direct physical access. Because of this, samples of ingesta cannot easily be collected and analyzed,” explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research.

One way that veterinary researchers circumvent the need to have direct physical access to each section of the tract involves the use of chemically labeled markers.^* These markers can be deposited into the stomach or placed directly in the cecum and colon of horses fitted with permanent ports that allow researchers actual windows to these portions of the hindgut. The markers are then measured in fecal samples to determine how long it took to travel through each region of the gastrointestinal tract.

An improved understanding of the flow of digesta through the gastrointestinal tract using labeled markers or other techniques, such as computer-modeling programs, will provide invaluable information for formulating diets and maximizing feed efficiency.

“While researchers continue to work on transit times of fiber through the gastrointestinal tract, one key way of maximizing the health and fiber-fermenting efficiency a horse’s hindgut is by offering adequate amounts of quality forage and supplementing with EquiShure,” said Crandell.

EquiShure influences the pH of the cecum and colon through a buffering mechanism, which allows beneficial bacteria, including those that ferment fiber, to perform optimally.

“Disruptions in hindgut pH, and therefore the bacterial population, can be minimized during times of stress, such as traveling, weaning, changes in herd dynamics, and periods of stall rest,” noted Crandell. “EquiShure is especially useful when diet changes are necessary or when horses are fed diets high in soluble carbohydrates to fuel performance.”

^*Hansen, T.L., J.M.  Bobel, E.M. Rankins, L.C. Sanchez, and L.K. Warren. 2020. A pilot study exploring the relationship between digesta retention time in the equine gastrointestinal tract and compartment models. Journal of Equine Veterinary Science 88:102941.