Are Horses Ruminant Animals?

Horses are not ruminant animals. Typical ruminants such as cows and sheep have specialized digestive systems which allow them to ferment their herbivorous food intake. Horses are also types of herbivorous animal, but their unique gastrointestinal anatomy distinguishes them from traditional ruminant animals.

Ruminants are known for their unique digestive process, which involves the aforementioned fermentation of food. This fermentation takes place in a series of stomach compartments. The food is then partially regurgitated for additional chewing. This process allows for a more complete breakdown of plant fiber and more efficient absorption of nutrients.

Horses do not share these distinctive characteristic of ruminants. Instead of having multiple stomach compartments like ruminants, horses have a single stomach. This stomach is divided into three main sections. This means the digestive sytsm of horses is more similar to that of other monogastric mammals, such as dogs and humans, than to that of ruminant animals.

The digestive process of horses focuses on the breakdown of food in the small intestine where nutrients are absorbed. Unlike ruminants, horses do not regurgitate their feed for additional chewing. Instead, they rely on microbial fermentation in the large intestine to break down plant fiber and extract nutrients.

You can read our related guide to learn more about the types of ruminant animals and how their digestive systems function.

As mentioned above, horses are monogastric animals. As with humans, this means horses have only one stomach. This does not mean horses and humans have the same gastrointestinal system. The digestive system of horses is adapted to process a herbivorous diet, specifically involving the breakdown of tough plant fibers. The horse's stomach is divided into two main sections:

• Glandular stomach: also known as the fundic region, it is the part of the horse's stomach that produces hydrochloric acid and digestive enzymes. These help in the breakdown of proteins and other food components. This section is similar to the stomach of humans and other mammals. It is where the food digestion process begins.
• Non-glandular stomach: also known as the squamous region, it lacks acid-producing glands and digestive enzymes. Instead, it has a protective layer of cells that help prevent damage caused by gastric acid. This section of the stomach is considered most susceptible to problems such as gastric ulcers.

After passing through the horse's stomach, digested food passes to the small intestine. It is in this part of the horse digestive system where most nutrient absorption occurs. Carbohydrates, fats and proteins are further broken down into smaller molecules that can be absorbed by the intestinal walls and used by the body for energy and nutrients.

In addition to the stomach and small intestine, horses also have a well-developed large intestine that plays a crucial role in their digestive process. The large intestine of horses is divided into the cecum, colon and rectum. In the large intestine, microbial fermentation breaks down plant fiber, producing volatile fatty acids that provide an additional source of energy.

Horses need such an extensive digestive system to breakdown the fibrous material of which their diet mainly consists. We discuss this diet in further detail with our article explaining what horses eat.

The differences between horses and ruminants is seen in the anatomy and physiology of their respective digestive systems, as explained above. Ruminants have a specialized digestive system that allows them to efficiently digest fibrous plant materials through a complex fermentation process involving multiple stomach compartments and regurgitation for additional mastication.

Compared to ruminants such as cows and sheep, the horse's digestive system is monogastric. This means it has only one stomach and does not have the ability to regurgitate and re-chew its food.

The main anatomical differences that distinguish the horse from ruminants include:

• Stomach compartments: while ruminants have several stomach compartments, such as the rumen, reticulum, omasum and abomasum, the horse has a single stomach. This stomach is divided into two main sections of the glandular stomach and the non-glandular stomach. This difference in stomach structure significantly affects the process of food digestion and fermentation.
• Fermentation process: ruminants carry out fermentation before the large intestine. It begins in the rumen where microorganisms break down the plant fiber before it passes to the small intestine for absorption. On the other hand, in the horse, the main fermentation of plant fiber occurs in the large intestine, especially in the cecum and colon, after the food has passed through the stomach and small intestine.
• Regurgitation and remastication: ruminants have the unique ability to regurgitate a portion of their partially digested feed from the rumen to masticate it again, facilitating the further breakdown of plant fiber. This allows them to extract more nutrients from plant-based foods. In comparison, horses do not have this capacity for regurgitation and remastication.

The horse digests food through a digestive process that involves different parts of their gastrointestinal system. In this way, we can say that it is made up of the following steps:

1. Consumption: when a horse eats, it first chews the food with their teeth to break it into smaller pieces. This initial chewing is important to increase the contact surface of the food and facilitate subsequent digestion.
2. Stomach: after chewing, food passes through the esophagus into the stomach. In the stomach, food is mixed with gastric acid and digestive enzymes produced by the gastric glands. This stage of the digestive process involves the breakdown of proteins and other food components.
3. Small intestine: from the stomach, partially digested food passes into the small intestine. This is where most nutrient absorption occurs. Digestive enzymes secreted by the pancreas and small intestine break down carbohydrates, fats and proteins into smaller molecules. These can then be absorbed by the intestinal walls and transferred to the bloodstream for use by the body.
4. Large intestine: after passing through the small intestine, undigested food reaches the large intestine. This is separated into several sections, including the cecum, colon and rectum. In the large intestine, microbial fermentation breaks down plant fiber, producing volatile fatty acids that can be used by the horse as an additional source of energy.
5. Excretion: undigested waste, including indigestible parts of the food and dead microorganisms, finally passes into the rectum and is expelled from the body as feces.

Horses have a digestive system designed to process a diet rich in plant fiber, such as hay and grass. Microbial fermentation in the large intestine is especially important for breaking down plant fiber and extracting essential nutrients from these foods.

Now we know that horses are not ruminant animals and have learned how the horse digestive system works, you may want to know more about other key horse behaviors. You can do so with our articles explaining how horses sleep and how horses mate.

If you want to read similar articles to Are Horses Ruminant Animals?, we recommend you visit our Facts about the animal kingdom category.