The sheep alimentary canal (digestive system) has evolved to
developing microbial flora (micro-organisms).
Sheep are herbivorous ruminants for that digest coarse, fibrous plants
to obtain the required amount of nutrients.
Ruminants are organisms that have four stomachs, the reticulum, rumen,
omasum and abomasum. In order for ruminants to digest plants efficiently a
large population of bacteria, anaerobic fungi and protozoa are located within
the rumen that performs microbial fermentation.
The function of microbial flora is to chemically breakdown carbohydrates
(cellulose and starch) and proteins because unlike other vertebrates, ruminants
cannot produce cellulose (an enzyme that digests cellulose).
A sheep will mechanically chew their food with their teeth. The saliva glands release enzymes to start the chemical process of digestion. The saliva (an alkali) lubricates the food to help the sheep swallow and keeps the stomach content liquid with a normal amount of acid.
The food will then travel down the oesophagus into the first stomach, the rumen. Here the food is mechanically churned and exposed to bacteria. The bacterium secretes enzymes to break down cellulose, sugar and starch (carbohydrates). This process is also known as foregut fermentation.
The processed food will then travel to the reticulum. The muscular walls will then regurgitate the food back to the mouth for further mechanical fermentation (rumination).
Then the omasum will remove 60-70% of the liquid content from the food.
The abomasum is known as the true stomach. The cells located on the stomach lining secrete gastric juices that contain lysozymes. The gastric juices; hydrochloric acid, will then start the digestion of proteins and also kills a majority of the microbes from the rumen.
Food is forced into the small intestine, which also secretes more enzymes that breaks down starch, protein and lipids into soluble compounds. They are then absorbed into the blood stream by the villi.
The rest of the undigested food residues, travel into the large intestine. Bacterium located here further digests more nutrients. More liquid is also removed here.
The waste products are then forced through the rectum and secreted through the anus as faeces.
http://www.mun.ca/biology/scarr/Ruminant_Digestion.html
APS Book: Nutrition; Ruminant digestion page 105-6
A sheep will mechanically chew their food with their teeth. The saliva glands release enzymes to start the chemical process of digestion. The saliva (an alkali) lubricates the food to help the sheep swallow and keeps the stomach content liquid with a normal amount of acid.
The food will then travel down the oesophagus into the first stomach, the rumen. Here the food is mechanically churned and exposed to bacteria. The bacterium secretes enzymes to break down cellulose, sugar and starch (carbohydrates). This process is also known as foregut fermentation.
The processed food will then travel to the reticulum. The muscular walls will then regurgitate the food back to the mouth for further mechanical fermentation (rumination).
Then the omasum will remove 60-70% of the liquid content from the food.
The abomasum is known as the true stomach. The cells located on the stomach lining secrete gastric juices that contain lysozymes. The gastric juices; hydrochloric acid, will then start the digestion of proteins and also kills a majority of the microbes from the rumen.
Food is forced into the small intestine, which also secretes more enzymes that breaks down starch, protein and lipids into soluble compounds. They are then absorbed into the blood stream by the villi.
The rest of the undigested food residues, travel into the large intestine. Bacterium located here further digests more nutrients. More liquid is also removed here.
The waste products are then forced through the rectum and secreted through the anus as faeces.
http://www.mun.ca/biology/scarr/Ruminant_Digestion.html
APS Book: Nutrition; Ruminant digestion page 105-6