TOPIC 02-NUTRITION -2
The ruminant digestive system
A ruminant is an animal that chews food, swallows it then returns it to the mouth later for further chewing. This is called chewing cud. Examples of ruminants are cows, goats, sheep, antelopes and giraffes.
The digestive system of a ruminant is different from that of a human being. Ruminants have a more elaborate system to enable cellulose digestion.
The stomach of a ruminant has four chambers: rumen, reticulum, omasum and abomasum.
When a ruminant first chews and swallows a mouthful of plant matter, the food enters the rumen. Bacteria in the rumen immediately start digesting the cellulose present in the material. Chewing cud softens and helps down plant fibres, making them more access to digestion by the bacteria. When the food in the rumen, it is coarse and very green. The food then regurgitated and chewed again. It passes the reticulum. The reticulum has a 'honeycomb" appearance. In the reticulum, the food is mixed thoroughly with water. The food coarse, more watery, less green and very small compared to the food in the rumen.
The food is regurgitated, chewed again and passed to the omasum. The abomasum has longitudinal folds like the leaves of a book. The folds help to remove water from the food. The food in the omasum is in form of fine particle and has very little water.
The abomasum is the ruminant's stomach. The abomasum has gastric acid facilitates the digestion of proteins. It also has microorganisms that may have spilled over the rumen.