(redirected from ruminal)
Also found in: Dictionary, Thesaurus, Medical.
Related to ruminal: ruminal acidosis, ruminal bacteria


(vertebrate zoology)
The first chamber of the ruminant stomach. Also known as paunch.



(also paunch), the first and largest section of the four-chambered stomach of ruminants. The rumen occupies almost the entire left half of the abdominal cavity. In adult animals its volume equals four-fifths the volume of the entire stomach. In newborns, which are fed only milk, the rumen is half the size of the abomasum. The first section of the rumen is connected to the reticulum and the esophagus. The rumen’s walls consist of the serous membrane (exterior membrane), the muscular membrane (middle membrane), and the mucous membrane (interior membrane). The interior wall has bands that divide the rumen into sacs, which slow down the movement of food. The interior epithelial surface, except for the bands, has processes, or papillae. In camels and llamas the walls of the rumen have deep cells, in the floors of which open cardiac glands. Such glands are absent in the rumens of other ruminants.

Decomposition of plant substances through bacterial and protozoan activity occurs in the rumen. Volatile acids are assimilated through the surface of the mucous membrane. The food is subjected to the action of enzymes and is mixed. From the rumen the food enters the reticulum or is regurgitated into the mouth, where it is masticated again. The food then passes into the omasum through the esophageal groove.

T. B. SABLINA [22–10101]

References in periodicals archive ?
Los datos de la degradacion ruminal de MS se calcularon por diferencia entre el peso inicial y final de cada muestra; la perdida de peso fue considerada como el valor de desaparicion de MS.
Clarification of the ruminal content started by separating manually solid from liquid part, this last was filtered to obtain a homogeneous liquid, that was 40% v/v.
Kim et al [12] first retrieved all the 16S rRNA gene sequences of both ruminal bacteria and archaea deposited in the RDP database and then conducted a meta-analysis of the retrieved sequences to examine the collective bacterial and archaeal diversity in the rumen.
Mean ruminal concentrations of volatile fatty acid (g fatty acid / 100 g total VFAs) and ammonia-N (mg/dl) of lambs fed diets containing different levels of NDF.
Excess ruminal ammonia can generate losses in both of energy and nitrogen, increasing the animal's energy cost, since the conversion of ammonia into urea costs 12 kcal[g.
On day 1, 28, and 56 of the experiment, samples of whole ruminal contents were collected from 9 lambs of each group, before the morning feeding and 3 and 6 hours after feeding.
The ruminal epithelium works as a defensive barrier between the ruminal environment and portal circulation (Graham and Simmons, 2005).
Se hace necesario profundizar en el estudio de esta patologia y conocer como los actuales sistemas de alimentacion de toros de lidia influyen en la misma, para buscar un sistema que permita conseguir el volumen y el trapio exigidos sin alterar la fisiologia ruminal, buscando con ello mejorar el rendimiento de los animales durante la lidia.
Entre los parametros de la cinetica ruminal de la MS y la PC (Cuadro 2) se tiene que, la fraccion soluble (a) a los 135 dias de rebrote fue de 24.
Surgical management of ruminal fisula due to traumatic injury by iron rod near to the last left intercostal space in a cow (Prakash and Ravi, 2009), ruminal fistula along with impaction due to plastic sheets, wires and twisted ropes (Rameshkumar et al.