Agriculture Reference
In-Depth Information
into molecules, which are made up of groups of atoms. This process is called
digestion, and it has mechanical, chemical, and biological components.
Like cows, goats, and deer, sheep are members of the class of animals
known as
ruminants,
who have a unique, four-stomach digestive system.
The First Phases of Digestion
The top of the mouth in the front of ruminants is a hard palate — they don't
have any front teeth on top, though they have top teeth in the back of their
mouths. The bottom teeth tear and grind feed against the top palate, providing
the mechanical component of the digestive process. Initially, the food is only
lightly chewed and combined with saliva to form a small ball, or bolus, of feed.
The sheep swallows this bolus, and it enters the rumen, or fi rst stomach.
The Rumen
The rumen is like a biological factory, where microorganisms work to break
down feed through a fermentation process. We're inclined to think of all bugs
(that is, bacteria and other microorganisms) as bad, but those that normally
reside in the rumen are not only benefi cial; they are absolutely essential to the
animal's survival. These bugs are called fl ora and have evolved through a mutu-
ally benefi cial, or symbiotic, relationship with the sheep over many aeons.
rumen
esophagus
cecum
reticulum
large
intestine
omasum
small
intestine
abomasum
Digestion in sheep is a complex process that takes place in a four-part stomach
system. The four parts are the rumen, reticulum, omasum, and abomasum.
