Digestion+in+ruminants

=Digestion in Ruminants=



** THE RUMINANT DIGESTIVE SYSTEM   **

  The fact that the ruminant can convert roughages, unsuitable for man, into useful products is normally taken for granted. What enables them to achieve this? The ruminant has three preliminary compartments in its digestive tract before the true stomach, or abomasum. These are the reticulum, rumen, and omasum. The rumen, and reticulum are not completely separated, but have different functions. >  Reticulum >  The reticulum is a flask-shaped compartment with a "honeycomb" appearance. It moves ingested food (ingesta) into the rumen and the omasum. The reticulum also causes the regurgitation of ingesta during rumination, and acts as a collection compartment for foreign objects. >  **Rumen** >  The rumen is a large fermentation chamber (in adult cattle its volume is about 125 litres) which has a very high population of micro-organisms, mainly bacteria, but also protozoa. >  It is because the bacteria secrete the enzymes necessary for cellulose degradation that ruminants are able to utilize roughage. The rumen has a textured surface, lined with projections (up to 1 cm long), termed rumen papillae. The rumen, along with the omasum, absorb the by-products of bacterial fermentation. These by-products are volatile fatty acids (VFAs). >  Omasum >  The omasum, or "manyplies", contains numerous laminae (tissue leaves) that help grind ingesta. These folds assist in the removal of fluid from the ingesta on their way to the abomasum. > >  Abomasum >  This compartment corresponds to the stomach of the non-ruminant, and is termed the true stomach. It secretes the gastric juices which aid in digestion. >  >   > **  STOMACH OF THE NEWBORN CALF   ** > >   Calves, at birth, are not functional ruminants. At birth, the rumen is very small, and the fourth stomach (or abomasum) is by far the largest of the compartments. Digestion in the young calf is more like that of a simple-stomached animal than that of a ruminant, and it takes approximately three to four months before the calves can be considered actual ruminants. >  >   Videos [] []

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