Page 113 - Agriculture_Form_Three

Agriculture for Secondary Schools

(d) Abomasum: This is the chamber that in the fore-stomach which is indicated
connects the stomach to intestine via by red and blue arrows. In the rumen,
the duodenum. It is sometimes called the digesta is worked on by the rumen
the true stomach and is very similar to microbes which breakdown the cellulose
the stomach of non-ruminants (refer to into simple sugars consumed by the
Figure 5.5). It produces highly acidic microbes. Through this fermentation,
gastric juices and enzymes which help volatile fatty acids (acetic, propionic and
in further digestion of the feedstuff. The butyric acids) are produced, absorbed
microbes that arrive with feed from the through the rumen and reticulum walls
three chambers are destroyed by the and utilised as energy source. Along
abomasum acidic fluids. Proteins are with the fatty acids, some gases, such
also denatured and digested here and are as carbon dioxide and methane are
prepared for absorption that will follow also produced. The gases are expelled
in the small intestines. from the rumen through the mouth by
eructation.

Digestion in the abomasum and small
intestine
Within the abomasum and the small
intestine, digestion in ruminants is similar
to that of non-ruminants. Ruminants
benefit from microbial cells that have
been carried with digesta from the fore-
Figure 5.5: Abomasum
Digestion processes in the fore-stomach stomach. These microbes are digested
by the host animal to produce the amino
of a ruminant acids which are absorbed along the walls
The chewed food material is swallowed of the small intestine.

via the oesophagus into the first chamber
of the stomach, that is, the rumen. Digestive system and digestion in
Materials that are partially chewed or not monogastric herbivores
sufficiently grinded known as ‘the cudʼ Monogastric hervivores do not possess
are sent back into the mouth through the four chambers like ruminants. They
reverse peristalsis, that is, backward have simple stomach but also have the
propulsion (regurgitation). While in the ability to use hindgut to ferment or break
mouth, the feedstuff is finely grinded down roughages. Farm animals with
and mixed with additional saliva and this kind of digestion include rabbits,
guinea pigs, donkeys and horses. Figure
reswallowed back into the rumen. Refer 5.6 shows a typical digestive system
Figure 5.1 to observe digestion process monogastric herbivores.

Student’s Book Form Three
102

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