Ruminants

Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in the front part of the digestive system and therefore is called foregut fermentation, typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of rechewing the ingesta to further break down plant matter and stimulate digestion is called rumination or chewing the cu

thumb|right|Animal rennet to be used in the manufacture of cheddar cheese

The rumen, also known as a paunch, is the largest stomach compartment in ruminants. The rumen and the reticulum make up the reticulorumen in ruminant animals. The diverse microbial communities in the rumen allows it to serve as the primary site for microbial fermentation of ingested feed, which is often fiber-rich roughage typically indigestible by mammalian digestive systems. The rumen is known for containing unique microbial networks within its multiple sac compartments to break down nutrients into usable energy and fatty acids.

thumb|right|The ruminant digestive system The abomasum, also known as the maw, rennet-bag, or reed tripe, is the fourth and final stomach compartment in ruminants. It secretes rennet, which is used in cheese creation.

Pecora is an infraorder of even-toed hoofed mammals with ruminant digestion. Most members of Pecora have cranial appendages projecting from their frontal bones; only two extant genera lack them, Hydropotes and Moschus. The name "Pecora" comes from the Latin word , which means "cattle". Although most pecorans have cranial appendages, only some of these are properly called "horns", and many scientists agree that these appendages did not arise from a common ancestor, but instead evolved independently on at least two occasions. Likewise, while Pecora as a group is supported by both molecular and m

thumb|right|The ruminant digestive systemThe omasum, also known as the green, the fardel, the manyplies and the psalterium, is the third compartment of the stomach in ruminants. The omasum comes after the rumen and reticulum and before the abomasum. Different ruminants have different omasum structures and function based on the food that they eat and how they developed through evolution.

second chamber in the four-chamber alimentary canal of a ruminant animal

Tragulina (also known as Traguliformes) is an infraorder of even-toed ungulates. Only the chevrotains survive to the present, including the genera Tragulus (the mouse deer) and Hyemoschus, all within the family Tragulidae.

Cud is a portion of food that returns from a ruminant's stomach to the mouth to be chewed for the second time. More precisely, it is a bolus of semi-degraded food regurgitated from the reticulorumen of a ruminant. Cud is produced during the physical digestive process of rumination.

Leptomerycidae is an extinct family of ruminants endemic to North America during the middle Eocene to middle Miocene, making it the longest-living group of ruminants on the continent. Members of the group are medium sized mammals similar in shape to the modern mouse deer, a group which it has been suggested to have been related to, but there were a number of differences. These would mostly be present in the skull with these animals heavily reducing their canines, in contrast to the large canines seen in their relatives. Similar to their overall body shape, members of the family are generally c