rumen,ruminal fluid,parts in rumen,microbes involved in rumen,microoorganisms present in ruminal fluid

1. RUMEN
BY SREEREMYA.S

3.  Ruminants are mammals that are able to acquire
nutrients from plant-based food by fermenting it in a
specialized stomach prior to digestion, principally
through bacterial actions. The process typically requires
the fermented ingesta (known as cud) to be regurgitated
and chewed again. The process of rechewing the cud to
further break down plant matter and stimulate digestion
is calledrumination. The word "ruminant" comes from
the Latin ruminare, which means "to chew over again".
 There are about 150 species of ruminants, which include
both domestic and wild species. Ruminating mammals
include cattle, goats,sheep, giraffes, yaks, deer, camels, ll
amas, antelope, and some macropods.

4.  Taxonomically, the suborder Ruminantia (also
known as Ruminants) is a lineage of
herbivorous artiodactylas that includes the most
advanced and widespread of the
world's ungulates.The term 'ruminant' is not
synonymous with Ruminantia.
Suborder Ruminantiaincludes many ruminant
species, but does not
include tylopods and marsupials, which are
technically ruminants.

5. Food digestion in the simple stomach of non-ruminant
animals versus ruminants

6.  The primary difference between a ruminant and
non-ruminant is that ruminants have a four-compartment
stomach. The four parts of the
stomach are the rumen, reticulum, omasum,
and abomasum. In the first two chambers, the
rumen and the reticulum, the food is mixed
with saliva and separates into layers of solid and
liquid material. Solids clump together to form the
cud or bolus.

7.  The cud is then regurgitated and chewed to completely
mix it with saliva and to break down the particle size.
Fiber, especially cellulose and hemi-cellulose, is
primarily broken down in these chambers by microbes
(mostly bacteria, as well as
some protozoa, fungi and yeast) into the three volatile
fatty acids (VFAs): acetic acid, propionic acid andbutyric
acid. Protein and non-structural carbohydrate
(pectin, sugars, starches) are also fermented.

8. Classification and Taxonomy
 Hofmann and Stewart divided ruminants into three
major categories based on their feed type and feeding
habits: concentrate selectors; intermediate types;
and grass/roughage eaters, with the assumption that
feeding habits in ruminants cause morphological
differences in their digestive systems, including
salivary glands, rumen size, and rumen papillae

9.  There are also pseudoruminants, which have a three-compartment
stomach instead of four like
ruminants. Tylopoda (comprising Camelids)
and Hippopotamidae (comprisinghippopotami) are well
known examples. Pseudoruminants, like traditional
ruminants, are foregut fermentors and most ruminate or
chew cud. However, their anatomy and method of
digestion differs significantly from that of a four-chambered
ruminant.