User:Sunandshade/cecal

cecal sandbox

Cecotrope (main, production) *****************************

Cecotropes, also called caecotrophs, caecal pellets, cecals, or night feces, are the product of the cecum, a part of the digestive system in mammals of the order Lagomorpha, which includes two families: Leporidae (rabbits and hares), and Ochotonidae (pikas). Cecotropes are passed through the intestines and subsequently reingested for added nutrients in a process known as "cecotrophy", "cecophagy", "pseudorumination", "refection", coprophagia or "coprophagy". Reingestion is also practiced by a few species of rodent (such as the beaver, capybara, and guinea pig), some marsupials (the common ringtail possum (Pseudocheirus peregrinus) and possibly the coppery ringtail possum (Pseudochirops cupreus)) and one species of primate (the sportive lemur (Lepilemur mustelinus)).

The process by which cecotropes are produced is called "hindgut fermentation". Food passes through the esophagus, stomach, small intestine, where nutrients are initially absorbed ineffectively, and then into the colon. Through reverse peristalsis, the food is forced back into the cecum where it is broken down into simple sugars (i.e. monosaccharides) by bacterial fermentation. The cecotrope then passes through the colon, the anus, and is eliminated by the animal and then reingested. The process occurs 4 to 8 hours after eating. This type of reingestion to obtain more nutrients is similar to the chewing of cud in cattle.

Coprophagia (intro; By vertebrates) *****************************

Some animal species eat feces as a normal behavior, in particular lagomorphs, which do so to allow tough plant materials to be digested more thoroughly by passing twice through the digestive tract.

Species within the Lagomorpha (rabbits, hares, and pikas) produce two types of fecal pellets: hard ones, and soft ones called cecotropes. Animals in these species reingest their cecotropes, to extract further nutrients. Cecotropes derive from chewed plant material that collects in the cecum, a chamber between the large and small intestine, containing large quantities of symbiotic bacteria that help with the digestion of cellulose and also produce certain B vitamins. After excretion of the soft cecotrope, it is again eaten whole by the animal and redigested in a special part of the stomach. The pellets remain intact for up to six hours in the stomach; the bacteria within continue to digest the plant carbohydrates. This double-digestion process enables these animals to extract nutrients that they may have missed during the first passage through the gut, as well as the nutrients formed by the microbial activity. This process serves the same purpose within these animals as rumination (cud-chewing) does in cattle and sheep.

Note that while coprophagia refers to eating any feces, cecotrophy (caecotrophy) refers specifically to eating cecotropes (material fermented in the cecum).

rabbit (digestion, merge starting paragraphs) *****************************

Rabbits are herbivores that feed by grazing on grass and other leafy plants. Consequently, their diet contains large amounts of cellulose, which is hard to digest. Rabbits solve this problem via a form of hindgut fermentation. They pass two distinct types of feces: hard droppings and soft black viscous pellets, the latter of which are known as cecotropes or "night droppings" and are immediately eaten (a behaviour known as cecotrophy ). Rabbits reingest their own droppings (rather than chewing the cud as do cows and numerous other herbivores) to digest their food further and extract sufficient nutrients.

Rabbits graze heavily and rapidly for roughly the first half-hour of a grazing period (usually in the late afternoon), followed by about half an hour of more selective feeding. In this time, the rabbit will also excrete many hard fecal pellets, being waste pellets that will not be reingested. If the environment is relatively non-threatening, the rabbit will remain outdoors for many hours, grazing at intervals. The rabbit will reingest its soft, partially digested pellets in a process known as cecotrophy; this is rarely observed, since the pellets are reingested as they are produced.

Hard pellets are made up of hay-like fragments of plant cuticle and stalk, being the final waste product after redigestion of soft pellets. These are only released outside the burrow or form and are not reingested. Soft pellets are usually produced several hours after grazing, after the hard pellets have all been excreted. They are made up of micro-organisms and undigested plant cell walls, among other necessary nutrients.

Rabbits are hindgut digesters. This means that most of their digestion takes place in their large intestine and cecum. In rabbits, the cecum is about 10 times bigger than the stomach and it along with the large intestine makes up roughly 40% of the rabbit's digestive tract. The unique musculature of the cecum allows the intestinal tract of the rabbit to separate fibrous material from more digestible material; the fibrous material is passed as feces, while the more nutritious material is encased in a mucous lining as a cecotrope. Cecotropes, sometimes called "night feces", are high in minerals, vitamins and proteins that are necessary to the rabbit's health. Rabbits eat these to meet their nutritional requirements; the mucous coating allows the nutrients to pass through the acidic stomach for digestion in the intestines. This process allows rabbits to extract the necessary nutrients from their food.

The chewed plant material collects in the large cecum, a secondary chamber between the large and small intestine containing large quantities of symbiotic bacteria that help with the digestion of cellulose and also produce certain B vitamins. The pellets are about 56% bacteria by dry weight, largely accounting for the pellets being 24.4% protein on average. The soft feces form here and contain up to five times the vitamins of hard feces. After being excreted, they are eaten whole by the rabbit and redigested in a special part of the stomach. The pellets remain intact for up to six hours in the stomach; the bacteria within continue to digest the plant carbohydrates. This double-digestion process enables rabbits to use nutrients that they may have missed during the first passage through the gut, as well as the nutrients formed by the microbial activity and thus ensures that maximum nutrition is derived from the food they eat. This process serves the same purpose in the rabbit as rumination does in cattle and sheep.

domestic rabbit (digestion) *****************************

Rabbits are hindgut fermenters and therefore have an enlarged cecum. This allows a rabbit to digest, via fermentation, what it otherwise would not be able to metabolically process.

After a rabbit ingests food, the food travels down the esophagus and through a small valve called the cardia. In rabbits, this valve is very well pronounced and makes the rabbit incapable of vomiting. The food then moves to the stomach and small intestine, where a majority of nutrient extraction and absorption takes place. Food then passes into the colon and eventually into the cecum. Peristaltic muscle contractions (waves of motion) help to separate fibrous and non-fibrous particles. The non-fibrous particles are then moved backwards up the colon, through the illeo-cecal valve, and into the cecum. Symbiotic bacteria in the cecum help to further digest the non-fibrous particles into a more metabolically manageable substance. After as little as three hours, a soft, fecal "pellet," called a cecotrope, is expelled from the rabbit's anus. The rabbit instinctively eats these pellets (shaped like a tiny cluster of grapes), without chewing, in order to keep the mucous coating intact. This coating protects the vitamin- and nutrient-rich bacteria from stomach acid, until it reaches the small intestine, where the nutrients from the cecotrope can be absorbed.

The soft pellets contain a sufficiently large portion of nutrients that are critical to the rabbit's health. This soft fecal matter is rich in vitamin B and other nutrients. The process of coprophagy is one of the important ways to supply the rabbit's digestive health with vitamin B in a form that is digestible. Occasionally, the rabbit may leave these pellets lying about in its cage. In moderate amounts, this behavior is harmless, although it may be indicative of too many carbohydrates in the diet.

When caecal pellets are wet and runny (semi-liquid) and stick to the rabbit and surrounding objects, they are called intermittent soft cecotropes (ISCs). This is different from ordinary diarrhea and is usually caused by a diet too high in carbohydrates or too low in fiber. Soft fruit or salad items such as lettuce, cucumbers and tomatoes are possible causes.

Lagomorpha (digestion) *****************************

Like other herbivores, lagomorphs have to deal with a bulky diet in which the cell walls are composed of cellulose, a substance which mammalian digestive enzymes are unable to break down. Despite this, lagomorphs have developed a way of extracting maximum nourishment from their diet. First they bite off and shred plant tissues with their incisors and then they grind the material with their molars. Digestion continues in the stomach and small intestine where nutrients are absorbed. After that, certain food remains get diverted into the caecum, a blind-ended pouch. Here, they are mixed with bacteria, yeasts and other micro-organisms that are able to digest cellulose and turn it into sugar, a process known as hindgut fermentation. Other faecal matter passes along the colon and is excreted in the normal way as small, dry pellets. About four to eight hours after the meal, the contents of the caecum pass into the colon and are eliminated as soft, moist pellets known as cecotropes. These are immediately eaten by the lagomorph, which can thus extract all the remaining nutrients in the food.

Leporidae (characteristics) *****************************

Both rabbits and hares are almost exclusively herbivorous (although some Lepus species are known to eat carrion), feeding primarily on grasses and herbs, although they also eat leaves, fruit, and seeds of various kinds. They are coprophagous, as they pass food through their digestive systems twice, first expelling it as soft green feces, called cecotropes, which they then reingest, eventually producing hard, dark fecal pellets.

Ochotonidae, Pika (characteristics) *****************************

Like rabbits, after eating they initially produce cecotropes, which they eat again to take in further nutrition before producing the final solid fecal pellets.