rumen

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Related to rumens: ruminant digestion

rumen

(rū'men),
The anaerobic fermentative fore stomach of ruminants that consists of anatomically and functionally indistinct chambers; important role in the predigestion of the cellulose rich diet of herbivores. In addition to the specialized anatomic pouches, a rich biodiverse population of protists, viruses, fungi, bacteria, and enzymatic cofactors mix with water and alkaline saliva (during rumination) serves as a microenvironment within which volatile fatty acid (VFA) end-products (e.g., butyric acid, valeric acid) are generated (along with by-products such as belched or eructated methane and fine textured ingesta that passes to the rear gut to complete digestion and form feces). Average rumen holds 40 gal or 160 L of ingesta. Compartments include the reticulum and rumen (proper); rumen is compartmentalized by anterior and posterior pillars. Ventral and dorsal coronary pillars divide off the ventral and dorsal blind sacs, and by longitudinal pillars, which divide the main rumen compartment into the dorsal and ventral sacs, as well as the omasum and abomasum (the latter is the true monogastric type stomach).
See also: ruminant.
[L. throat, gullet]

rumen

(ro͞o′mən)
n. pl. ru·mina (-mə-nə) or ru·mens
The first division of the stomach of a ruminant animal, in which most food collects immediately after being swallowed and from which it is later returned to the mouth as cud for thorough chewing. Also called paunch.

ru′mi·nal adj.

rumen

a branch of the oesophagus of ruminants in which unchewed food is stored temporarily and from which it is regurgitated to the mouth for chewing (see RUMINANT STOMACH). Some cellulose is digested and absorbed in the rumen and bacterial action results in the synthesis of B vitamins there. Cellulase is produced by bacteria which may number 1 billion per cm3 in the rumen.

rumen

pl. rumens, rumina; the largest of the compartments of the forestomach of ruminant animals that serves as a fermentating vat. It is lined by a keratinized epithelium bearing numerous absorptive papillae; it is partly subdivided by folds (pillars). These include dorsal and ventral sacs and a caudodorsal blind sac and a caudoventral blind sac. It communicates directly with the reticulum cranially and has no other exit. It covers most of the floor of the adomen on the left in the nonpregnant animal and in animals not affected by left displacement of the abomasum. Caudally it may reach the brim of the pelvis and is palpable rectally.

rumen transplant
see cud transfer.
References in periodicals archive ?
Each pair read, scaffold, and contig of the shotgun sequencing of goat rumen microbes was summarized in Supplementary Figure 1 and Supplementary Table 1.
The isolated genes in rumen fluid were classified into a total of 1,704 organisms, among which each 181 and 1431 ID corresponded to plant and bacteria, respectively.
DFM that target the rumen must be active in the rumen and remain viable during delivery, therefore studies of DFM are limited to few species.
Other distinctive bacterial species such as Megasphaera elsdenii and Prevotella bryantii have also been used as DFM to stabilize or improve rumen function.
The amount of CHO digested in the rumen was calculated using the equation
The amount of CP digested in the rumen was calculated using the following equation:
To quantitatively predict nutrient supply, both in the rumen and intestines, several sophisticated models exist.
Three dry Holstein-Friesian cows fitted with large rumen cannulas with an internal diameter of 10 cm were housed in tie stalls and bedded with straw at the dairy experimental station of the University of Saskatchewan.
Therefore, the objective of this study was to evaluate the effect of sulfur on utilization efficiency of fresh cassava foliage and cassava hay in milking dairy cows, on i) rumen pH, ammonia nitrogen, total volatile fatty acids, cyanide concentration and microflora population and microbial protein synthesis ii) nutrient digestibility iii) serum concentration of urea nitrogen, thiocyanate, thyroid gland hormones and liver enzymes and iv) milk production and composition.
Rumen microbial fermentation supplies host animals (ruminants) with volatile fatty acids (VFAs) and microbial proteins as fermentation products.
Russell describes the rumen, largest of the four stomach compartments of ruminants, as "a mysterious black box.