Having a little one in the house, I am fairly well acquainted with checking teeth every night before bed. I’ve explained that it is important to do this – even if they are going to end up in the custody of the tooth fairy at some point. But while teeth are so critical for us as mammals, it might surprise you the amount of creatures on our planet that don’t have teeth.
Aside from the reports of some mutant strain, chickens do not have teeth. And this is a good thing. Their beaks are made of Keratin – the same material that human hair and fingernails are made of. This material is ideal for their repetitive pecking at the ground as it is constantly growing. However, if a chicken were to have teeth located in their beak, then these teeth would eventually be pushed out by the constant extending growth of the beak.
As hens are already using a considerable amount of calcium to produce egg shells, the additional calcium requirements to regularly grow new teeth would be quite demanding.
### Important Note ###
For a very brief time, a chick will have a single tooth, called the egg tooth. This small bone rests on the outside tip of the chick’s upper beak and is used to help them break free of the egg. Remember, egg shells are made of calcium so it only makes sense that chicks would need something tough to break through.
The egg tooth falls off shortly after hatching, leaving a little white area that is still visible for a few more days.
How Do Chickens Eat Without Teeth?
How many times have you heard (or said) ‘take smaller bites’ or ‘chew your food!’ to some little child? My son will grab a bite of food and be running before he even gets it all the way into his mouth. Which of course, leaves me praying in earnest that he doesn’t trip and accidentally inhale something.
Biting and chewing for us (or least adults) is so natural, most of us don’t even think about it. It just happens. But if chickens don’t have teeth, then how are they breaking their food down?
With regards to the work of our incisors, chickens utilized two main techniques to make things small enough to swallow – they will peck at it and break it down… or they will bashitto where it tears apart.
- Pecking – A good example of this is an apple. If you slice an apple in quarters, so that the soft part of the apple is accessible, and then toss these quarters to your flock, you will see your birds using their beaks to peck at the soft insides of the apple. This causes small little pieces of apple to fly off, allowing your chickens to consume them.
- Bashing – Though I don’t recommend excessive amounts, you can best see this bashing process with a full sized piece of bread. There is no way a chicken is going to be able to swallow a whole piece of bread and as a result, they have to break it down.
Grabbing the bread with their beaks, they will lift the food slightly and then with a quick downward motion, bash the bread against the ground. Sometimes this process is accompanied with a slight twist, but regardless, this bashing motion will continue until things are either bite sized or the chicken decides to give up.
With regards to the work of our molars, the grinding process of food happens in the chicken’s gizzard. Strong muscles in this organ, work at mashing contents into smaller and malleable parts.
### Important Note ###
Chickens will also bash bugs on the ground before trying to swallow them. This not only makes the meal easier to swallow, but protects the chicken from getting hurt by an insect that isn’t ready to be lunch. For example, you can expect to see a Praying Mantis take a significant bashing before the bird is ready to send it down.
Do Chickens Need To Eat Rocks?
As mentioned above, the chicken’s gizzard is where the real force is applied towards breaking food down. However, while mammals have hard teeth to crush things, there are no teeth in the gizzard. To put this in perspective, imagine trying to eat a steak without teeth. While the steak might taste really good, you are definitely going to be ‘gumming’ things for a quite a while.
Chickens compensate for this lack of molars by consuming small pieces of grit. This can be sand, dirt or even small pebbles. Without this roughage in their gizzard, things would be very difficult for them. (Think of trying to ‘gum’ a steak).
In a free range environment, this gritty roughage is generally easily obtained. However, supplemental grit is often recommended for birds that are confined, or – as in the case of northern climates – the roughage is buried under several feet of snow.
How Many Stomachs Does A Chicken Have?
This can be a tricky question as chickens are not mammals – and as such, plumbing is a little different.
There are two organs in a chicken that break food down – the proventriculus and the ventriculus (gizzard).
Both of these organs have specific jobs, however, it’s arguable as to whether or not they are comparable to the human stomach. Remember, the ventriculus (aka, gizzard) is where the food is ‘chewed’. This organ actually comes after the proventriculus – where acid is added to soften the food. So in this case, a chicken is essentially chewing the food that has already passed through the acid bath in the proventriculus.
This is exactly opposite of how mammals break down food (told you the plumbing was different).
A Chicken’s Digestive System
It might be easiest to understand things if we started at the food end of chicken and worked our way on through to the poo end. Of course there are many organs involved such as the spleen, liver and pancreas. However, for the sake of simplicity, we are going to focus on the primary path of food through the chicken.
- The Beak – This is where it all begins. Food is obtained, made bite-sized by either pecking or bashing and then ready to move on.
- The Tongue – While a chicken’s tongue is not as capable as ours, it still works to move food towards the back of the throat where things can be swallowed. For an in-depth look at this, read ‘Does A Chicken Have A Tongue?’
- Esophagus – In this particular case, the esophagus works for the chicken just like it does in mammals. It carries the food from the mouth down to where it needs to go next.
- The Crop – To understand a crop, think of a chipmunk with it cheeks stuffed full of seeds/acorns. There isn’t a whole lot that goes on inside the crop. But it does allow the bird to collect a bunch of food quickly.
- The Proventriculus – With a short pause at the crop, food jumps back onto the esophagus and continues down the proventriculus. This is where the bulk of digestive fluids enter picture. Food is softened by the acid and then sent further down.
- The Ventriculus – Directly underneath the proventriculus is ventriculus. Here is where the softened food is mashed and essentially broken down.
- The Small Intestine – Attached to the bottom of the ventriculus is the small intestine. This organ functions pretty much like ours and is the path for mashed food to follow.
- The Ceca – Much like the crop, the two Ceca are not through pathways. They are simply organs where food can go up for a little more work. The Ceca are located at the junction of the small and large intestines.
- The Large Intestine – The large intestine (which ironically is smaller than the small intestine) is the last stop for food before it exits. It acts just like our large intestine.
- The Cloaca – The cloaca is the final organ in the path for food and is a very multipurpose part of a chicken. Not only is it the ‘exit’ for food, but it also is the pathway for other things. What is especially unique is that the cloaca is basically the same for both male and female chicken.
For example, while a hen may receive sperm and pass her eggs through the cloaca, the rooster will also use the cloaca to pass sperm onto the hen. In this regard, the cloaca is the same, however the male and female have different plumbing attached.
To get an in-depth look at this, read ‘How Do Chickens Mate?’