Horses are non-ruminant herbivores also known as a “hindgut fermenters.”
Their digestive tract is made up of a simple stomach, small intestine and large intestine.
The natural feeding habit of the horse is to eat small amounts of roughages often. Domestication has brought a change to this. Modern management practices of horses incorporate stabling, increased grain-based concentrate consumption, meal feeding and limited access to pasture. This has led to a myriad of problems by undermining the horses’ digestive capabilities.
By understanding the basics of their digestive tract we are better able to make more appropriate feeding and management choices.
The stomach of the horse is small in relation to the rest of the digestive tract and limits the amount of feed that can be consumed at one time. Another limitation to the stomach, compared to other species, is that the horse cannot regurgitate food if they overeat or consume something poisonous. The average-sized horse (1,100lb) has a stomach capacity of approximately four gallons. Once the stomach becomes two-thirds full it begins to empty whether the food has been sufficiently broken down or not.
In the stomach, food is mixed with pepsin (an enzyme to digest proteins) and hydrochloric acid to help break down solid particles. The rate of passage of food through the stomach is highly variable, depending on how the horse is fed. Passage time may be as short as 15 minutes when the horse is consuming a large meal.
The small intestine is made…