Ruminantia
White -tailed deer (Odocoileus virginianus)
- Mouse deer ( Tragulidae )
- Forehead weapons carrier ( Pecora ) Giraffe -like ( Giraffidae )
- Musk deer ( Moschidae )
- Gabelhorn carrier ( Antilocapridae )
- Deer ( Cervidae )
- Bovidae ( Bovidae )
Ruminants ( ruminant ) are a suborder of Ungulates ( Artiodactyla ). They are herbivores and have a multipart ruminant stomach that allows them by microbial digestion to take advantage of such carbohydrates as food that are indigestible to other mammals with only one stomach ( monogastric ) ( for example, cellulose). Ruminants are divided into two groups Chevrotain and forehead weapons carrier.
In addition to ruminants and other herbivores such as kangaroos, Slim monkeys, horses and lagomorphs capable of cellulose by microorganisms to digest, but in the colon, resulting in a further passage through the digestive tract needed makes for recoverability of microbial protein ( Caecotrophie ).
The term ' ruminant ' comes from the fact that the pre-digested chyme is regurgitated during rest of the animal and chewed again before further mechanically comminuted food swallowed again and the actual digestion is supplied.
Construction of the stomach
The ruminant stomach usually consists of four sections: the abomasum ( abomasum ) corresponds to the einhöhligen stomach of monogastric animals. Upstream there are three fore-stomachs, where it is different differentiated portions of the esophagus: the rumen (also: Zottenmagen Rumen ), reticulum (also: hood, reticulum ) and omasum (also: Book stomach, psaltery, Omasus ). The rumen in turn has an atrium, which is also referred to as spin stomach. This can also be counted separately, thereby reducing the number of rumen on four or the stomachs to five. Occasionally, rumen and reticulum are grouped functionally for Reticulorumen.
While browsing the plant food is chewed and swallowed only roughly. Then passes through the centrifugal stomach into the rumen. In the rumen, but also in the other fore-stomachs, numerous live microorganisms such as bacteria, protozoa, and yeasts with which the chyme is mixed well. The microorganisms are capable of degrading most of the carbohydrate substances which can be absorbed by the rumen wall. In this process also known as fermentation, carbohydrates are digested, which are indigestible for other species ( for example, cellulose), so that it can accommodate the ruminants and use energy. The liberated during the fermentation gases (mainly carbon dioxide and methane) accumulate in the dorsal rumen sac until they are released by the eructation ( belching ) to the environment. The biosynthesis of amino acids of microorganisms is stimulated by excreted with the saliva or the rumen or fed fed urea, so that ruminants can survive entirely without supplied amino acids.
The chyme is now available for further crushing and mixing between the rumen and reticulum reciprocated before it is transported by contractions of the reticulum and spin stomach and backwards, peristaltic waves of the remaining esophagus in small portions back into the oral cavity. The food is here by further chewing ( rumination ) more finely crushed before being swallowed again.
The reticulum exerts a " sorting function", which retains large and coarsely chopped food components and transports small particles in the omasum on. There, the chyme is squeezed by contraction between the leaves and absorbed the water, which the chyme thickens and ensures that the digestive secretions are diluted in the following abomasum less. Finally, the digested food is transported into the abomasum where - is lowered the pH by secretion of hydrochloric acid and digestion, especially of proteins and fats, is made by the body's enzymes - as well as in the monogastric animals. There are also proteins from the microorganisms present in the chyme are released, which are absorbed in the adjoining small intestine.
Due to the long residence time of food in the ruminant stomach, where it is constantly mixed and finally whether or not concentrated, often form Bezoarsteine . In these " stomach stones " is swallowed hair and plant fibers to stick together and stick together and finally are getting harder.
System
One can divide the ruminant into two groups:
- The mouse deer ( Tragulidae ) are the most primitive group. For them, the omasum is missing.
- The frontal armor-bearer ( Pecora ) always have vierkammerigen stomach described above. Named giving feature in these animals are the most existing end weapons. They can be divided into five families: Giraffe -like ( Giraffidae )
- Musk deer ( Moschidae )
- Gabelhorn carrier ( Antilocapridae )
- Deer ( Cervidae )
- Bovidae ( Bovidae )
Animals with similar digestive system
Regardless of the ruminant some other animal groups have also developed a chambered stomach, with which they digest the food in much the same way. These include camels, hippos, peccaries, sloths, Slim and colobus monkeys and kangaroos. The Hoatzin digested similar to ruminants, but here the lower end of the esophagus and the crop are transformed into rumen.
The whales are related to hippos and have inherited from their land-dwelling ancestors the chambered stomach. However, your stomach does not work as ruminant stomach, because they feed on animal food. Gray whales, Greenland whales and minke whales use bacteria to digest the Chitinskelett of krill.