1 chew the cuds; "cows ruminate"
2 reflect deeply on a subject; "I mulled over the events of the afternoon"; "philosophers have speculated on the question of God for thousands of years"; "The scientist must stop to observe and start to excogitate" [syn: chew over, think over, meditate, ponder, excogitate, contemplate, muse, reflect, mull, mull over, speculate]
- To chew cud. (Said of ruminants.) Involves regurgitating partially
digested food from the
- A camel will ruminate just as a cow will.
- To meditate or reflect.
to chew cud
A ruminant, from a physiological point-of-view, is any artiodactyl mammal that digests its food in two steps, first by eating the raw material and regurgitating a semi-digested form known as cud from within their first stomach, known as the rumen. The process of again chewing the cud to break down the plant matter and stimulate digestion is called ruminating. Ruminating Mammals include cattle, goats, sheep, giraffes, American Bison, European bison, yaks, water buffalo, deer, camels, alpacas, llamas, wildebeest, antelope, and pronghorn. However, from a zoologial and evolution point-of-view, the suborder Ruminantia includes all those species except the camels, llamas and alpacas, which are Tylopoda. Therefore, 'Ruminant' (physiology) is not synonymous of Ruminantia (taxonomy).
ExplanationRuminants have a fore-stomach with four chambers. These 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). The cud is then regurgitated, chewed slowly to completely mix it with saliva and to break down the particle size, Fiber, especially cellulose and hemi-cellulose, is primarily broken down into the three volatile fatty acids, acetic acid, propionic acid and butyric acid in these chambers by microbes (bacteria, protozoa, and fungi). Protein and non-structural carbohydrate (pectin, sugars, starches) are also fermented.
Even though the rumen and reticulum have different names they represent the same functional space as digesta can move back and forth between them. Together these chambers are called the reticulorumen. The degraded digesta, which is now in the lower liquid part of the reticulorumen, then passes into the next chamber, the omasum, where water and many of the inorganic mineral elements are absorbed into the blood stream. After this the digesta is moved to the last chamber, the abomasum. The abomasum is the direct equivalent of the monogastric stomach (for example that of the human or pig), and digesta is digested here in much the same way. Digesta is finally moved into the small intestine, where the digestion and absorption of nutrients occurs. Microbes produced in the reticulo-rumen are also digested in the small intestine. Fermentation continues in the large intestine in the same way as in the reticulorumen.
Almost all the glucose produced by the breaking down of cellulose and hemicellulose is used by microbes in the rumen, and as such ruminants usually absorb little glucose from the small intestine. Rather, ruminants' requirement for glucose (for brain function and lactation if appropriate) is made by the liver from propionate, one of the volatile fatty acids made in the rumen .
Religious importanceIn Abrahamic religions, a distinction between clean and unclean animals approximately falls according to whether the animal ruminates. The Law of Moses in the Bible allowed only the eating of animals that had split hooves and swallowed their food multiple times, a stipulation preserved to this day in the Kashrut. The close relation to rumination is apparent in many English translations of the Bible, which use the word cud in an expanded sense to indicate food that is re-chewed through either rumination or the process used by lagomorphs.
Other usesThe verb to ruminate has been extended metaphorically to mean to thoughtfully ponder or to meditate on some topic. Similarly, ideas may be chewed on or digested. Chew the (one's) cud is to reflect or meditate.
ruminate in Czech: Přežvýkavec
ruminate in Danish: Drøvtygger
ruminate in Spanish: Rumiante
ruminate in Esperanto: Remaĉuloj
ruminate in French: Ruminant
ruminate in Korean: 반추 동물
ruminate in Icelandic: Jórturdýr
ruminate in Dutch: Herkauwers
ruminate in Japanese: 反芻
ruminate in Polish: Przeżuwacze
ruminate in Portuguese: Ruminantes
ruminate in Vietnamese: Động vật nhai lại
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