What is Rumination: Definition and Process | Ruminant Digestive System

In this blog, we are going to learn what is rumination, and ruminant digestive system. We will also get an overview about the process of rumination in ruminants.

What is Rumination?

The process whereby the cud stored in the rumen returns to the mouth and is re-chewed to further break down the plant matter and stimulate digestion is called rumination. The process of rumination is exclusive to ruminants.

Now that you have understood what is rumination, let us learn about ruminants.

What are Ruminants?

Ruminants are herbivores mammals that get nutrients from plant-based food by fermenting them into a particular stomach before digestion. The word ‘ruminant’ is obtained from the Latin word ruminare, to chew again. Ruminants are animals who have four-chambered stomachs, which allows them to chew food more than once.

The ruminants or ruminant animals swallow their food fastly without chewing, and later regurgitates it or brings it back up into the mouth, then chew it, and finally re-swallows it.

Examples of Ruminants

Some examples of ruminants are cattle, sheep, antelopes, deer, buffalo, giraffes etc.

Ruminant Digestive System

It is interesting to note that digestion in cows and other ruminants like sheep, cattle, camels, giraffes, etc is different from that in humans. You must have observed them chewing continuously even when they are not eating. Let us see the reason behind it. To understand it better, let us see the passage of food in the digestive tract in ruminants.

The food is first chewed partially in the mouth and sent through the esophagus to a separate part of the stomach called the Rumen. Actually, the grass-eating animals quickly swallow the grass and store it in the rumen. Here, the digestive juices partially digest the food which is present in the rumen and is then called the cud.

You must be wondering why the grass-eating animals digest the food partially without chewing. The reason is, if they continue grazing for a long time, they can become easy targets for their predators. They, therefore, use their ability to ruminate to protect themselves from predators.

Rumination and Ruminants

You already know that the grass-eating animals are called ruminants and have also studied how they quickly swallow and partially digest the grass to form cud. Later on, this cud returns to the mouth in small lumps, and the ruminant chews it. It is now that the food is chewed nicely.


You know that ruminants feed on grasses for their food. The grasses are rich in cellulose which is a type of carbohydrate. Many animals, including humans, cannot digest cellulose. However, the ruminants can. Actually, in ruminants there is a sac like structure called the’caecum’ which is a pouch connected to the large intestine and ileum.

It is the beginning of the large intestine. In ruminants the caceum is greatly enlarged and houses around 70 different kinds of bacteria. The caceum, therefore serves as a storage organ that permits bacteria and other microbes to digest the cellulose. In this way, the grasses are digested in the caecum.

Importance of Rumination

Rumination is a kind of adaptation for herbivore animals so they can spend minimum time feeding. Feeding is considered a vulnerable time for animals as the predators can attack them easily when the animals are busy eating. Rumination is done by animals so they can graze in a safer environment with ease.

Read More- Human Digestive System- Parts and Functions | Process of Digestion

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