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Agriculture for Secondary Schools

swallowing or upwards into the mouth (b) Reticulum: This is sometimes called
during regurgitation. Regurgitation is a the honey-comb stomach (refer to Figure
process by which ruminants bring back 5.3). It is the chamber next to the rumen;
feed materials from the rumen to the the two being separated by just a small
mouth for grinding into finer particles. muscular groove. The reticulum’s main
The materials are swallowed back into functions are to send back to the rumen
the rumen for the digestion process to particles that are too large for the digestion
continue. process and collection of finer particles
from which further nutrient absorption
The stomach: The ruminant stomach is shall continue. Because of their closely
relatively large and is divided into four related functions, sometimes the rumen
chambers that are rumen, reticulum, and the reticulum are known as reticulo-
omasum and abomasum.
rumen chamber.
(a) Rumen: This is the first and largest
chamber of ruminant stomach located on
the left side of the body. It is connected
to the mouth via the oesophagus. The
rumen surface is covered by projections
called papillae which help to increase
the surface area for chemical activities
and nutrient absorption (refer to Figure
5.2). The rumen has two main functions Figure 5.3: Reticulum
that are fermentation and storage. (c) Omasum: This is the chamber next
Within the rumen there are symbiotic to reticulum. It is sometimes named as
microorganisms including bacteria, book-stomach because the inside lining
protozoa and fungi, whose function is to of the chamber has long folds of tissues
help in the breakdown and fermentation that are arranged like pages of a book
of the feedstuffs. (refer to Figure 5.4). The main function
of omasum is to reabsorb water and
some nutrients.

Figure 5.2: Rumen

Figure 5.4: Omasum
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