rumen


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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]
Farlex Partner Medical Dictionary © Farlex 2012

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.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

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.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
There are numerous studies showing beneficial effects of herbs and plant extracts on feed intake, immune functions and health, rumen fermentation and productivity of calves, dairy cows, heifers and also beef cattle (Cardozo et al., 2006; Devant et al., 2007; Fandino et al., 2008; Greathead, 2003; Vakili et al., 2013; Yang et al,.
However, with PRF, the greatest sample amount (2.6g of DM 100 [mL.sup.-1] of rumen fluid) resulted in lower (P<0.05) C[H.sub.4] production (mL [g.sup.-1] of DMI), but the amounts of 0.6 and 1.3 (g of DM 100[mL.sup.-1] of rumen fluid) were not significantly different from each other for C[H.sub.4] production (P>0.05).
To achieve this level of bypass protein, we can fall into feeding a high level of overall crude protein (both rumen available and bypass protein) which can be expensive, detrimental to the environment and may encourage a loss of body condition in early lactation cows.
"The big task of the leaders is not for today, but to see what awaits us tomorrow," Rumen Radev pointed out and urged the young people to preserve their critical thinking and to stand up for their ideas.
When ruminant are fed with feed containing protein, the first stage is microbial degradation which make it complex to quantify the utilized product in rumen. No method is available for NCG determination in rumen fluid.
The rumen microbial fermentation characteristics, including pH, gas production, N[H.sub.3]-N, microbial protein, VFA, acetate: propionate ratio, and C[H.sub.4] at 0, 2, 4, 8, 12, and 24 h, and the quantity of the rumen microbial DNA extracted from the rumen contents were analyzed statistically using the LSMEANS statement of the MIXED procedure in the SAS program package [24].
Rumen fluid was sampled approximately 2 and 6 h post-feeding via an esophageal tube on last day of each sampling period.
During the collection, water and feed were suspended to avoid interfering with rumen volume.
Cows that suffer sub-acute rumen acidosis reduce production triggered by inconsistent feed intake, poor feed efficiency and reduced feed digestibility.
Despite that the rumen ciliate protozoa make a substantial portion of rumen biomass, little is known on their specific development conditions, inter-community interactions, and effects on rumen fermentation due to their complex morphology (Newbold et al., 2015; Zhang et al., 2007).