Starch: is it the same as sugar for a horse?

You often hear or read that it's not good for horses to consume a lot of sugars. This also applies to sugars from concentrated feed with a lot of grains. The digestive system and metabolism of horses are not well adapted to this. But what about starch? Is it different in this case?


14 June '24 3 min reading time

The short answer is "no," it's not different. Starch is essentially viewed by the horse's body as sugar and is therefore just as bad. When looking at the ingredient list of a bag of concentrated feed, it's important to consider both the sugar content and the starch content. For a more detailed answer, let's delve deeper into what "sugar" actually is and how a horse processes it.

All Carbohydrates

Sugar, starch, and glucose are all forms of carbohydrates. Here's a brief explanation:

Sugars: These are simple carbohydrates, such as fructose (fruit sugar) and glucose. They give food a sweet taste and are immediately available as an energy source. Sugars are found in fruit, some vegetables, and naturally in sugar cubes.

Starch: Starch is a complex carbohydrate made up of long chains of glucose molecules. It is found in grains and corn, for example. Starch must first be broken down into glucose before it can be used as energy. In mammals, this digestion occurs in the small intestine.

Glucose: Glucose is the primary fuel for our bodies. It is a smaller molecule released from starch and transported through the bloodstream as blood sugar. Body cells absorb glucose to produce energy. When glucose is stored in the body, it becomes glycogen.

In short, sugars are simple carbohydrates, starch is a complex carbohydrate, and glucose is the direct energy source for body cells.

Small Intestine or Large Intestine?

Oats, barley, and corn contain as much as 40, 50, and 65 percent starch. These grains are commonly used ingredients in concentrated feed for horses. To extract energy from starch, humans can convert starch into glycogen, which then enters the blood as an energy source. This conversion mainly occurs in the small intestine. However, in horses, digestion works very differently than in humans, with a much smaller role for the small intestine. Horses primarily digest food in the large intestine. This contains many microorganisms such as bacteria, yeasts, and fungi, which play an important role in the horse's digestion. The gut flora convert fibers into sugars and fatty acids. These substances are then absorbed by the horse to extract energy.

A Small Amount of Starch is Manageable

If there is starch in your horse's feed, it must be processed in the small intestine. The large intestine, where roughage is largely processed, is not suitable for this. After the feed passes through the stomach, the starch granules from the grains are digested in the upper part of the small intestine. The digestibility varies per type of grain. For instance, a horse can process oats quite well, but the starch granules from corn and barley are less than 30% digestible. When grains are processed using heat (extrusion), the starch becomes more digestible for horses, but a horse can always only digest a limited amount of it. If the starch flows undigested into the large intestine, it can disrupt the gut flora there, leading to acidosis. This causes various problems, including more waste products in the blood.

Starch as an Energy Source?

Although some (top) sport horses and lactating mares can use some sugars and starch from grains as quick energy, grain-free feed is sufficient for most recreational horses and horses in lower sports classes. Ensure that your horse gets enough vitamins and minerals. This is easiest to achieve with a balancer pellet. If you want to give your horse concentrated feed, pay attention to both the sugar content and the amount of starch in the product.

Questions? AskHELTIE!

Are you looking for advice about your dog or horse? Or do you want to know more about conditions or ingredients? Feel free to contact AskHELTIE, and we will be happy to assist you! .