Gastrointestinal Motility Key to Horse Digestive HealthBy Kentucky Equine Research Staff · May 2, 2016
A finely honed nervous system helps direct gastrointestinal function in horses. Referred to as the “brain of the gut,” the enteric nervous system monitors the goings-on of the entire tract, from beginning to end. One feature of the enteric nervous system is its ability to precisely coordinate the passage of ingesta from one digestive organ to the next. As horse owners, we can do little to alter or outsmart this innate wiring, but management approaches are available that maximize gastrointestinal motility.
Gastrointestinal motility refers to the passage of ingesta through the digestive tract by normal nervous and muscular functions. How to maximize gastrointestinal motility in horses rests largely with understanding how horses should be fed.
Horses are physiologically hardwired for continual consumption of forages. Because they evolved as grazing animals, horses have small stomachs that are kept nearly full at all times. This continuous flow of ingesta keeps the gastrointestinal tract moving normally. A well-functioning tract is a healthy tract.
Horses sometimes run into trouble when they are removed from situations that imitate natural foraging behaviors and instead are given two or three large meals a day. For a tract designed to be churning 24/7, fits-and-starts feeding might prove problematic, including:
- The longer the horse stands with nothing to eat, the more likely it is to develop gastric ulcers. In natural grazing situations, horses take long breaks from foraging, sometimes an hour or two. Few pastured horses will go without grazing for 8 to 10 hours, yet stabled horses often go this long between meals. Without the buffering defense of saliva and forage, the acidic fluid can irritate the stomach lining, often to the point of ulceration.
- Confined horses often develop stable vices, such as wood-chewing and cribbing, when fed meals. Horses with limited access to long-stem forage, such as hay, are particularly predisposed to these vices. Other horses will engage in coprophagy, or manure-eating, which is neither normal nor healthy in adult horses, especially if a strict deworming protocol is not in place.
- Horses that are stabled and fed intermittently are more prone to colic. In multiple studies, meal-feeding has been indicated as a predisposing factor.
- The exercise horses receive while grazing is thought to positively impact gastrointestinal motility.
What management tactic can help keep ulcers, vices, and colic at bay? If you guessed free-choice access to forage, you’re right!
Selecting the right forage for a horse depends largely on its energy needs. A hard keeper might require a calorie-dense legume, like alfalfa (lucerne) or clover, or lush pasture. On the other hand, an overweight pony might do well on a mid-quality hay and very little pasture. By allowing near continuous access to forage, the gastrointestinal tract chugs along consistently, the state in which it is most healthy.
Horses on an all-forage diet should be fed a well-formulated vitamin and mineral supplement to ensure optimal nutrition. Consider using Micro-Max or I.R. Pellet to make up for these shortages. Micro-Max is suitable for all mature horses. Like Micro-Max, I.R. Pellet can be fed to any adult horse, but it has been specifically formulated to help horses predisposed to metabolic disorders.
Do you have a question about how to feed your horse to keep its digestive tract healthy? Contact a KER nutrition advisor today!