Animals are fascinating in countless ways. But one of most fascinating things that is so different to humans is that some animals have more than one stomach.
There are hundreds of animals with more than one stomach, and we can find them everywhere. It seems that one stomach is not enough for animals like:
Multiple stomachs allow these animals to properly digest their food and avoid dehydration. For dairy animals, their multiple stomachs ensure safe milk consumption for humans.
How do these animals with multiple stomachs function? Keep reading to find out.
What Are Ruminants and Camelids?
The term “multiple stomachs” usually refers to compartmentalized stomachs with different sections for different purposes. Animals with multiple stomachs are called ruminants and camelids; the former has four compartments while the latter has three.
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Examples of ruminants (4 stomachs) are:
Examples of camelids (3 stomachs) are:
How many animals with more than one stomach does the world have? There are only six species in the Camelidae family. For ruminants, there are around 200 species in six families.
Why Do Some Animals Have More Than One Stomach?
It’s not a mistake of nature that causes some animals to have multiple stomachs. Herbivores primarily eat plants and grass, such as animals like:
The plants these animals eat are tough to digest, and it takes longer for the food to travel through their intestines. Having more than one compartment in their stomachs allows these animals to stay healthy and hydrated.
Proper Digestion and Nutrition
Poor digestion can cause various problems for animals. This especially applies to herbivores since their diet is mainly composed of plants, which are not easy to digest and mostly come from poorer-energy nourishment. Animals with multiple stomachs can properly digest their food and absorb more nutrients from plants.
Herbivores need to extract water from the plants, and they typically do this through constant chewing. The cud that comes out of their mouths is partially-digested food and saliva.
The cud is then chewed again to extract more water before it’s finally swallowed. This helps in further fermentation, which happens in one of the stomach compartments.
The process of extracting water from plants helps these animals stay hydrated, especially in dry environments. It also removes all bacteria and helps with more water retention.
Safe Human Milk Consumption
Dairy animals like cows, goats, and sheep have multiple stomachs for another purpose: to produce milk that is safe for humans to consume.
Animals with one stomach might have harmful bacteria in their dairy products since it’s not fully digested. The multiple stomachs of these animals help with better digestion and the removal of bacteria, making the milk clean and safe for humans.
How Do Animals With Multiple Stomachs Digest Their Food?
Having multiple stomach compartments means having a different digesting process. Since ruminants and camelids have different numbers of stomachs, their digestion also differs.
The four compartments of a ruminant’s stomach are the:
The largest is the rumen, which can hold at least 25 gallons of material. It stores food and is also the primary fermentation vat.
The next compartment is the reticulum, a pouch-like structure that has a network of tissues. It catches the dense feed and prevents it from going back to the rumen.
After the reticulum is the omasum, which acts as a strainer. Water and other nutrients are absorbed in this compartment before it goes to the abomasum.
The abomasum is the fourth and final stomach, and it’s similar to the human stomach. This is where digestion and absorption of nutrients happen before it enters the small intestine. The abomasum is also called the “true stomach.”
The stomach compartments of camelids are called the:
C-1 is the first and largest compartment on the animal’s left side. It takes up 80% of the stomach’s total volume, functioning as the fermentation vat that houses friendly microorganisms. Six hours after the ingested food enters and stays in C-1, it goes to the C-2.
C-2 is the main digestion chamber where water and other nutrients are absorbed. This compartment prepares the material for final digestion, which occurs in the last compartment, C-3.
C-3 takes up 11% of the total forestomach volume, and it’s the camelid’s “true stomach.”
Ultimately, the purpose of multiple stomachs is plant fiber fermentation. Since plant fiber is herbivores’ most important dietary component, their stomachs need to properly break it down. Animals with numerous stomachs can do this efficiently, which is how they survive and thrive in various environments.
NOTE: Not all animals with multiple stomachs are herbivores. Some animals that require multiple stomachs are carnivores and omnivores.
Which Animals Have Multiple Stomachs?
It’s not just cows, goats, and sheep that have multiple stomachs. Other animals also have more than one stomach, like:
Learning the purpose of having multiple stomachs for every animal makes them even more fascinating! Let’s find out which animals have more than one stomach and why.
As mentioned above, cows are ruminants and have four stomach compartments. They’re also herbivores that are mostly fed on grass.
Since their diet consists of plant fiber, they need multiple stomachs to help with digestion. Cows eat for about six hours a day and chew cud for about eight hours. It’s no wonder why they need more than one stomach!
Like cows, deer are also ruminants with four stomach compartments. Their diet consists of:
- other plant materials
Deer need multiple stomachs to help digestion, and they also spend a lot of time chewing their cud.
Similar to cows and deer, goats are ruminants. They’re also mostly herbivores, and their diet consists mainly of grass though they also eat:
Like cows, goats need multiple stomachs to help with plant fiber digestion.
Another entry for the cud chewers, sheep have four stomach compartments. Like the other ruminants, sheep are herbivores that thrive by eating plants, and also chew their food and regurgitate it, so they can chew them again until it completely breaks down.
The largest ruminant in the world is the giraffe. Their long necks give them an advantage when eating leaves from the tallest trees.
Just like other ruminants, giraffes have four stomach compartments. The only difference between giraffes and other ruminants is probably their height since giraffes are the tallest animals in the world!
Giraffes eat fruits and twigs, which need multiple stomachs for digestion, and can eat 145 pounds of food daily, so one stomach definitely isn’t enough for them.
Moose are undeniably big animals. In fact, they’re the largest member of the deer family.
Like other members of the deer family, moose have four stomach compartments. Moose are mostly herbivores, but they’re also known to eat insects and fish.
Sloths are tree-dwelling animals native to the rainforests of Central and South America. Since they are known as slow animals, it’s no surprise they have a slow metabolism and digestive system, too.
Sloths have four stomach compartments that can digest tough and rubbery leaves!
Moving on from the ruminants, we have whales. These massive creatures have one stomach divided into compartments. For example, the cachalot or sperm whale has four stomachs. Since it’s not a herbivore, its digestive system works differently from ruminants.
Sperm whales have teeth, but they can’t really chew their food. Instead, they gulp large amounts of water and prey, which are then stored and crushed in the rumen.
The second stomach chamber called the “cardiac stomach” is responsible for producing the acid and enzymes needed for digestion. After the food is further digested in the second and third chambers, it finally enters the fourth.
Another whale that needs to be mentioned is Baird’s beaked whale. Like sperm whales, they have teeth but can’t chew their food. They also have one stomach that’s divided into two: the main stomach and a pyloric stomach.
What makes this whale even more incredible is that they have several small connecting stomach chambers. If you add up all the stomach chambers, Baird’s beaked whale has a total of 13!
All the fish and squid these whales eat go through each stomach compartment to give them the nutrition they need to live.
Similar to whales, dolphins don’t chew their food. These highly intelligent aquatic mammals have double-chambered stomachs.
The fundic chamber is big enough to store all the food a dolphin can eat in one meal. Meanwhile, the pyloric chamber is where all the digestion and absorption of nutrients happen.
The multiple stomachs of dolphins result from the evolution of a terrestrial predecessor. Some dolphin species also have three stomach chambers, which are responsible for digesting what they eat, including:
Llamas are closely related to camels and have three stomach compartments. They are camelids, along with:
Llamas are mostly used as pack animals in the Andes, but they’re also used for their meat and wool. Llamas are mostly herbivores; their diet consists of:
- other plants
A hippopotamus has three stomach compartments:
- parietal blind sac
- glandular stomach
They’re omnivores, which means they eat both plants and animals. However, most of their diet consists of plants.
Hippos are called “pseudo-ruminants” because they only have three stomach chambers but function similarly to ruminants. They are semi-aquatic animals that are good swimmers, and they don’t chew the grass and crops they eat.
Alligators are carnivores that have a two-chambered stomach. Like birds, they have gizzard stones to grind the food for digestion.
Alligators eat chunks of meat and tear their prey apart using their powerful jaws. The stomach compartments digest the food and absorb the nutrients even if they don’t really chew the meat.
Kangaroos hop around the Australian Outback using their powerful hind legs. Like other marsupials, they have two stomach compartments.
FUN FACT: Kangaroos graze on grass and leaves but don’t chew cud as often as ruminants do.
The flightless birds, known as ostriches, have three stomach compartments.
Ostriches don’t have teeth, so they can’t chew their food. To help them grind what they eat, in their gizzard they have:
Ostriches also have rough intestines, which allow them to digest things that other animals can’t. Their diet consists of:
Besides knowing camels as animals with humps, it’s also interesting to know that they have three stomachs.
Camels are found in dry, desert climates and can go for long periods (up to 15 days!) without water. They have three stomach chambers that allow them to digest and absorb nutrients from the scarce and poor food they eat.
Which Animal Has the Most Stomachs?
Out of the hundreds of animals with more than one stomach, it’s challenging to know which one has the most.
Some say it’s alligators, while others say it’s whales. Among the 15 animals listed above, the Baird’s beaked whale has the most stomachs. However, based on the “chambered section” stomach methodology, the answer will change.
The “chambered section” stomach methodology says that most stomachs are not fully functional, even if there is more than one.
Like the human appendix, most stomachs are just there to prevent infections but not to help digest food. If we’re going by that methodology, cows and goats have the most stomachs. It’s a win for ruminants!
Animals never run out of surprises. Many have more than one stomach, and their digestive systems are designed to help them get all the nutrition they need. The next time I spot an animal, whether big or small or tall or short, I’ll wonder, “How many stomachs does this animal have?”
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