Ruminants eat grass, forbs (broad-leaved plants), shrubs, and tree leaves/branches.

Yes, deer are ruminants. They have a multi-chambered stomach where the plant matter they eat gets broken down by fermentation in their foregut (rumen). They also chew cud. Deer are specialist ruminants in that they thrive on eating woody plants and forbs rather than a diet of mostly grass.

Yes, goats are ruminants. They have a multi-chambered stomach where the plant matter they eat gets broken down by fermentation in their foregut (rumen). They also chew cud. Like deer, goats are specialist ruminants in that they thrive on eating woody plants and forbs rather than a diet of mostly grass.

Yes, sheep are ruminants. They have a multi-chambered stomach where the plant matter they eat gets broken down by fermentation in their foregut (rumen). They also chew cud. They are less “specialized” than their distant cousins, goats, because they will eat a variety of plants from tree leaves to forbs to plenty of grass. 

Yes, giraffes are ruminants. They have a multi-chambered stomach where the plant matter they eat gets broken down by fermentation in their foregut (rumen).  Despite their long necks and gangly legs, they still chew cud, and will stand or lay in a quiet place away from predators (or at least try) to do so.

They are highly specialized ruminants, meaning they, like goats and deer, prefer a diet of tree leaves than any other plant. Very rarely do giraffes graze, sometimes they will eat brush if it’s tall enough and not going to impede on their constant watch for hungry predators. 

No, camels are not ruminants. They are pseudo ruminants, meaning that they lack a rumen but still chew cud. They still eat plants, but the fermentation occurs in the reticulum and omasum, the only forestomachs of a camelid. Alpacas and llamas are also pseud0-ruminants. 

No, elephants are “monogastrics,” meaning they have a large, well-developed simple stomach and large, functional ceca (singular: cecum) where most of the fermentation takes place. They are hindgut fermenters, like horses, rabbits, rhinos, and hippos. They do not chew cud, but have to eat a lot of plants to make up for their inefficiencies in being able to digest plants. They will engage on coprophagia (poop eating) to get extra nutrients they couldn’t get from just eating plants. 

No, rabbits are monogastrics. They have a simple stomach—hence the term “mono” (meaning one or single) and “gastric” (meaning stomach)—with large, functional ceca. Rabbits are, rather, hindgut fermenters. In their ceca, all fermentation occurs, further breaking down the plants they eat and releasing more nutrients into their bodies.

Rabbits engage in coprophagia (poop eating) to get more nutrients they can’t get from straight plants. Their “first poop” is called “pellets,” which is what they eat. The first poop is quite green in colour, which indicates plenty of plant matter that hasn’t quite broken down completely. Their second poop is much darker in colour, which rabbits won’t eat. 

Absolutely! The sole reason that ruminants have “multiple stomachs” or multi-chambered stomachs is so that they can make the most out of digesting plants. Plants are very hard to digest compared to meat because they have lignin and cellulose that give their cells important structure to stay upright. Ruminants need a fermentation vat full of billions of microorganisms to help them break down this tough plant material so that they can access the nutrients within the cells. 

Honestly, a ruminant wouldn’t be a ruminant if it weren’t an herbivore. However, not all herbivores are ruminants; several species are hindgut fermenters where the fermentation occurs in the ceca (which is attached to the colon), including rabbits, elephants, rhinoceros, hippopotamus, and horses. 

No, ruminants are foregut fermenters. Their true stomach, the abomasum, sits behind the other three forestomachs (reticulum, rumen, and omasum), as well as the rest of the digestive tract. Ruminants have ceca, but they play a minor role in fermenting plant matter compared to the rumen. The rumen is where almost all the fermentation occurs, housing billions of microorganisms responsible for the fermentation process. 

No, it’s the other way around: Cows are ruminants. Ruminants are members of the suborder Ruminantia (under Order Artiodactyla), which includes many bovine and non-bovine animals such as deer, sheep, goats, bison, elk, water buffalo, caribou (or reindeer), muskox, hartebeest, oryx, wildebeest, and many more. 

Definitely. All ruminants are under the taxonomic Kingdom Animalia. All ruminants are warm-blooded mammals that bear live young and produce milk. 

No. Horses (as well as donkeys, mules, burros, asses, and zebras) are hindgut fermenters, specifically monogastrics. The primary fermentation occurs in their ceca. 

No, pigs are monogastrics and omnivorous. Pigs will eat anything, from animals to fungi to plants. 

Only the young tend to be more capable of vomiting as opposed to older ruminants. It’s rare, but they may vomit if they have a stomach bug.

However, adult ruminants so-called “vomit” or regurgitate in order to chew cud. Digesta gets moved from the rumen into the reticulum, and the reticulum contracts in such a way where a “bolus” (or mouthful) of half-digested plant matter comes up the esophagus into the mouth where it gets chewed for a little bit of time, and reswallowed. 

No, it’s not the ruminant animal itself that digests cellulose, but rather the microorganisms in their rumen that do that job. Bacteria, fungi and protozoa all work together to break down the long-chain carbohydrate cellulose into simpler compounds called fatty acids (propionic, butyric and acetic). These are a main source of energy for ruminants and are absorbed into the bloodstream through the ruminal wall.

You’re talking about polychromasia, not polychromatic. This is a veterinary medicine term for red blood cells (erythrocytes) that appear bluish-gray under a microscope. These are immature red blood cells released by the bone marrow into the bloodstream, usually in response to anemia.

Thus, yes, ruminants certainly do exhibit polychromasia. This is how polychromasia works in ruminants:

It’s not the ruminants that break down cellulose, but rather their microorganism army in their rumens. Bacteria, fungi and protozoa all work together to break down the long-chain carbohydrate cellulose into simpler compounds called fatty acids (propionic, butyric and acetic). These are a main source of energy for ruminants and are absorbed into the bloodstream through the ruminal wall.

Ruminants have a complex process for digesting their food. Where mongastrics simply have their food go from mouth to stomach to intestines, and out as poop (liver, kidneys, pancreas and gall bladder play important roles along the way), ruminants have a few more steps added before their food even reaches their intestines. 

The ruminant grabs a mouthful of plant matter with its tongue, chews for a few seconds (the drier or harder the food, the longer the time to chew), then swallows. Ruminants produce a lot of saliva to help their food go down easily. Down the bolus goes into the reticulum, where it sits for a short time then moves into the rumen. The reticulum catches any foreign objects the ruminant may have accidentally swallowed, from metal bits to rocks.

Once in the rumen, the microorganisms (bacteria, fungi, and protozoa) get to work on their fresh food source and begin the breakdown process, called fermentation. You can think of it as an anaerobic (no oxygen) form of decomposition or “rotting,” and you’d still be correct. Ruminants are, basically, walking decomposition vats on four legs. 

Once the animal has eaten her fill, some of the partly “decomposed” or fermented plant matter moves back into the reticulum and then is brought up into the mouth to be chewed more thoroughly as “cud.” The ruminant will spend roughly 1 to 2 minutes chewing that cud before swallowing it and repeating the process with a new bolus. Depending on the species, most ruminants will spend somewhere between 30 and 60 minutes chewing their cud. Chewing the cud is the only time ruminants spend resting from eating, and they may sleep during that time as well. 

After the cud returns to the reticulum, it again makes its way back to the rumen to continue further breakdown by anaerobic microbes. Nutrients released from the fermentation process don’t always reach the abomasum (true stomach) and intestines before being absorbed into the bloodstream. In fact, some nutrients are released directly into the bloodstream from the rumen through the ruminal wall, particularly energy compounds and amino acids from both plants and dead microbes. However, there are still more steps to be taken before even more nutrients are released to the ruminant’s body. 

Digesta, as broken down as possible, move into the omasum. The omasum contains multiple folds of the epidermis, which are designed for high water absorption, along with some nutrient absorption. Removing the water portion of the digesta is important because it doesn’t mean the abomasum will be quickly filled up with mostly water and less digesta. Thus, once water has been removed from what is in the omasum, it is moved into the abomasum, where true digestion occurs. The abomasum functions like our stomachs, where enzymes are secreted to digest the digesta and extract proteins (amino acids) via peptides, with stomach acid. 

Then the digesta moves into the small intestine, where the majority of nutrient absorption occurs. Moving along into the large intestine, water is added back to the digesta, and more breakdown and absorption occur, turning the digesta into feces. Reaching the colon and finally the anus, it is excreted as feces. 

There is a lot more information on how ruminant digestion works, and you can read more about this on The Wonderful Ruminant Herbivore. 

Ruminants’ rumen microbes can turn hard-to-digest plants into usable nutrients that other non-ruminant animals find difficult to obtain. The multi-step process the plant material undergoes to be almost completely digested ensures that as many nutrients as possible are extracted before being deposited as poop. 

Ruminants can eat either living plants or dead plants and still survive; however, they thrive best on living plants rather than dead ones. This is because living plants contain more available nutrients and are easier to digest than dead plant matter. Dead plant matter has higher amounts of lignin and cellulose compared to nutrients, which makes it harder, though not impossible, to digest. Too much for too long, however, can be fatal, so ruminants still have to, somehow, find any source of nutritious, digestable plant matter they can find during seasons where living plants are difficult to find. 

Ruminants release methane by burping. Methane is produced mainly in the rumen; thus, the easiest way for this natural greenhouse gas to escape is from the rumen through the reticulum and esophagus out the mouth. Ruminants’ flatulence of methane is in much smaller amounts compared with belching. 

Rumens naturally burp once every minute.

Please check out How Ruminants Get Their Protein page to get your answer to this question!

In a nutshell, however, around 66% of a ruminant’s protein source comes from dead microbes. The rest comes from what those microbes could extract from the plants they eat.

Ruminants produce methane from the fermentation of plants in their rumens. The anaerobic fermentation of plant material by microbes produces gaseous byproducts, including methane and carbon dioxide. These get released via belching. 

Great question. Ruminants eat by wrapping their long, powerful tongues around their target mouthful of grass or leaves and then pulling it into their mouths, using their lower teeth to shear off what their tongues cannot pull away from the stem. They often make a head-nod motion to do this as they graze or browse.

All ruminants lack upper incisors (but not molars); instead, they have a tough top palate. They lack upper incisors, likely because they’re not needed for their grazing or browsing behaviours. 

Ruminants only have one stomach. They have three forestomachs in front of their main true stomach, which are extensions of the esophagus. 

Colloquially, the answer is four, however this is not morphologically, biologically nor technically true. 

ROO-muh-nahnt is how it is pronounced. 

“Small ruminants” is the term that livestock producers use to distinguish those ruminant animals that are less than 500 pounds in weight. These are sheep and goats. 

Non-ruminants are animals that do not have multi-chambered stomachs. They may be herbivorous (like horses, rabbits, elephants, or rhinos), omnivorous (humans, pigs, bears, raccoons, some birds, or rodents), or carnivorous (felines, canines, amphibians, birds, especially raptors, muskalids, whales, dolphins, porpoises, or reptiles).  

Pseudo ruminants are those that act like ruminants in that they are herbivorous and chew cud, but lack a rumen. Camelids (camels, alpacas, llamas and guanacos) fit into this category, and are the only animals that are classed as pseudo-ruminants. 

Large ruminants are those animals that weigh well over 500 pounds (up to 3600 lb) and stand over 4 to 5 feet at the shoulder. They include cattle, bison, buffalo, and some large antelope. Guar and banteng, which are in the buffalo family, are also large ruminants. 

Ruminants are known as foregut fermenters. 

The true stomach in ruminants is the abomasum. It sits between the omasum (third forestomach) and the small intestine, and operates just like our stomach does. 

Ruminants that chew the cud are often resting, and full from their last bout of grazing or browsing. 

Scientists believe ruminants started to evolve 50 million years ago as small forest-dwelling omnivores. The group that represents most of the ruminants we know today emerged during the Late Oligocene period, around 32 to 35 million years ago. 

Most of the protein ruminants get comes from dead and some living microbes in their rumen. A smaller percentage comes from plants. 

This occurs in the rumen. 

It depends on the species. Ruminants can live anywhere: on the tundra of the arctic, on wide open grasslands, in savannah, on steppe, in scrubland, areas with dense brush, in dense forests, in forest glades, in or near wetlands or moist grasslands, in deserts, in evergreen forests, in mixed deciduous and evergreen forests, on mountain slopes or cliffs, in foothills, as well as (for domesticated ruminants in particular) on farms and ranches in barns, on pastures, or man-made dirt corrals. Ruminants are found on all continents except Antarctica. 

There is more than just one animal that is classed as a ruminant. Check out THIS PAGE for a list of what animals are called ruminants.

All ruminants are mammals. Check out THIS PAGE for a list of what animals (mammals) are called ruminants.

The livestock that are ruminants are cattle, buffalo, sheep, and goats. 

There is more than just one species that is classed as a ruminant. Check out THIS PAGE for a list of what species are called ruminants.

All ruminants are ungulates. Check out THIS PAGE for a list of what animals are called ruminants.

You can call it evolution and adaptation to life on plants that are tough to digest. With the help of an army of billions of microbes in their rumen, they can turn cellulose into usable nutrients for their survival and beyond. Creationists will argue that it’s how they were designed by God, specifically for the purpose of eating plants and returning them to the soil. Call it what you will, the reasons are still a bit of a mystery by the greater scientific community. 

This adaptation allows the plants they just swallowed, nearly whole, to be rechewed and broken down further, so that more nutrients can be extracted by their anaerobic microbe army. 

Anaerobic fermentation in their rumens generates the byproduct gases methane and carbon dioxide due to microbial breakdown of plant matter. It’s just how ruminants break down and extract the nutrients their bodies need. 

It’s thought to come from observing their chewing and resting, which makes them look like they’re contemplating life’s mysteries. The word is thought to originate in the 1660s as a literal term used for these types of animals, derived from the 1530s word ruminate to describe a human behaviour of thinking very deeply about something. 

It’s part of their nature. They chew when they graze and browse, and chew more when they bring up and chew their cud. It’s also to keep their molars from growing too much and getting to sharp, so the chewing action coupled with the tough plant material keep molars in good enough shape for more chewing for another day. 

Regurgitation brings up a mouthful of partly digested plant matter which they chew as cud. 

Ruminants are valued not only for their meat, milk, wool, and ability to do work (especially cattle and buffalo), but also because they can turn an otherwise unsuitable resource, which we cannot eat or use ourselves on land that cannot be farmed with tender plants for our own palette, into a highly valuable source of food, fibre, and power. Even then, parts of the tender plants we cannot (or will not) eat get turned over to them to eat and turn into something valuable.

Their poop is also highly valued, used as fertilizer for the soil and, for those people who don’t have access to enough wood, to feed fires for cooking and to stay warm on cold nights. Dried buffalo or cattle “chips” are perfect fuel for fires.    

The rumen is the first (or second) forestomach in the ruminant’s digestive system. 

The rumen is the first (or second) forestomach in the ruminant’s digestive system. 

The rumen is the first (or second) forestomach in the ruminant’s digestive system.