Sheep are ruminant animals.
Their digestive tracts, which are similar to those of goats, cows and deer, consist of the mouth, oesophagus, four stomach compartments, small intestine and large intestine.
How Many Stomachs Does a Sheep Have?
Sheep technically only have one stomach, but it has four distinct compartments made up of the Rumen, Reticulum, Omasum and Abomasum. It is very different than a human stomach. That’s why people often say that a sheep has four stomachs.
SHEEP DIET
Grazing is a social behaviour like sheltering and camping. Domestic Sheep tend to have two main grazing periods, during the early morning and again late in the afternoon. The early morning grazing time tends to be a lesser active grazing time than the later period. Grazing time in total can last from 5 – 10 hours per day depending on breed of sheep and available pasture and water.
Sheep are exclusively herbivorous mammals.
Like all ruminants, sheep have a complex digestive system composed of four chambers, allowing them to break down cellulose from stems, leaves and seed hulls into simpler carbohydrates.
How Does a Sheep Eat?
When sheep graze, vegetation is chewed into a mass called a bolus, which is then passed into the first chamber: the rumen.
When sheep graze, vegetation is chewed into a mass called a bolus, which is then passed into the first chamber: the rumen.
The bolus is periodically regurgitated back to the mouth as cud for additional chewing and salivation.
Cud chewing is an adaptation allowing ruminants to graze more quickly in the morning and then fully chew and digest feed later in the day. This is beneficial as grazing, which requires lowering the head, leaves sheep vulnerable to predators, while cud chewing does not.
During fermentation, the rumen produces gas that must be expelled. After fermentation in the rumen, food passes into the reticulum and the omasum, special feeds such as grains may bypass the rumen altogether.
Following the first three chambers, food moves in to the abomasum for final digestion before processing by the intestines. The abomasum is the only one of the three chambers analogous to the human stomach (being the only one that absorbs nutrients for use as energy) and is sometimes called the ‘true stomach’.
Sheep need plenty of water, they also prefer to drink from running water such as brooks and streams rather than still sources. Sheep also require clean water and may refuse to drink water that is covered in scum or algae.
How does a Sheep Stomach Work?
Rumen: This is the largest of the four stomach compartments of ruminant animals. The capacity of the rumen of sheep ranges from 3 to 6 gallons depending on the type of feed. This compartment, also known as the ‘paunch’, contains many microorganisms (bacteria and protozoa) that supply enzymes to breakdown fibre and other food that the sheep eats. The conversion of the cellulose of feeds to volatile fatty acids (acetic, propionic, and butyric acids) is the result of microbiological activities in the rumen. These volatile fatty acids are absorbed through the rumen wall and provide up to 80 percent of the total energy requirements of the animal. Microbial digestion in the rumen is the basic reason why ruminant animals effectively utilize fibrous feeds and are maintained primarily on roughages.
Rumen microorganisms also convert components of the feed to useful products such as the essential amino acids, the B complex vitamins, and vitamin K. Finally, the microorganisms themselves are digested further in the digestive tract.
Reticulum: This compartment, also known as the ‘hardware stomach’ or ‘honeycomb’, is located just below the entrance of the oesophagus into the stomach. The reticulum is part of the rumen separated only by an overflow connection, the ‘rumino-reticular fold’. The capacity of the reticulum of sheep ranges from 0.25 to 0.50 gallons.
Omasum: This compartment, also known as the ‘manyplies’, consists of many folds or layers of tissue that grind up feed ingesta and remove some of the water from the feed. The capacity of the omasum in sheep is approximately 0.25 gallons.
Abomasum: This compartment is more often considered the ‘true stomach’ of ruminant animals. It functions similarly to human stomachs. It contains hydrochloric acid and digestive enzymes that breakdown food particles before they enter the small intestine. The capacity of the abomasum of sheep is approximately one gallon.