Why Don’t Cows Have Top Teeth? How Do They Eat?

If you’ve ever offered a cow a handful of hay, you’ve probably seen the cow stretch its neck toward you and reach with its tongue to pull that tasty hay into its mouth—a mouth with no top teeth! So, why don’t cows have top teeth? I recently had a friend ask me this question and I had to stop and think about it.

Cows actually do have some teeth in the upper jaw—just not in the center. Why don’t cows have top teeth in the front?

Cows don’t have front top teeth because they need a thick dental pad there instead. They use the dental pad—along with their bottom teeth—to grab grass, twist it, and pull it into their mouths with their rough tongues. Front teeth are usually incisor teeth, which cows don’t need because they eat and swallow their food quickly, without chewing it right away. They swallow each bite and store the grass in the first of their four stomachs. Later, they bring it back up—regurgitate it—and chew on it with their molars to break down the difficult-to-digest cellulose matter in the grass and pull out the nutrients. 

Let’s ruminate on why cows don’t have top teeth in the front, how many teeth cows do have, and what kinds of teeth they have for what purposes.

How Do Cows Eat Without Top Teeth? 

Cows don’t need their front-and-center top teeth because cows are ruminants. Ruminants are animals that eat grass, grain, and foliage. They have multiple stomachs. Ruminants swallow their food quickly and chew it later. Ruminants in the wild include pronghorns, giraffes, and antelopes. Domestic ruminants include sheep, goats, and cows.

If cows don’t have top teeth in the front, how do they get their food and nutrients? Here’s how cows eat grass:

• Taking a bite—Cows use their lips and rough tongue to grab and pull grass into their mouths.
• Using their pad—To tear off the grass, cows press their bottom teeth against what’s called a dental pad. The thick dental pad is along the top, front gumline where cows don’t have any teeth. The pad is hard and leathery. By pressing their bottom teeth against the top pad, they can tear the grass from the plant. The grass then mixes with the cow’s saliva, which contains enzymes that help break down the food.
• Swallowing—After each bite, cows will swallow their food right away. They don’t take time to chew it. The muscles in a cow’s esophagus function bidirectionally, which means food can be swallowed from the mouth to the stomach and again from the stomach to the mouth. (See Chewing its cud.)
• Storing the grass—Each bite travels down to a cow’s first of four stomachs, called the rumen, where it waits. (The other stomachs are called the reticulum, omasum, and abomasum.)
• Chewing its cud—When its first stomach is full, a cow meanders over to a shady place where it usually lays down to chew its cud. Chewing its cud means that the cow regurgitates the grass back up into its mouth, chews it a while, and swallows it again, repeatedly. They regurgitate about 50 times or for about six to eight hours per day. That’s nearly 30,000 chews. This chewing also stimulates saliva production. Adult cows can swallow up to 80 quarts of saliva a day. This repeated chewing breaks down the hard-to-digest cellulose matter, reduces the size of the food particles, and aids digestion. Bacteria and microorganisms in the stomachs also help break down the plant material. When ready, the cud moves to the other stomachs and the intestine for further breakdown and nutrient absorption.

How Many Teeth Do Cows Have?

Adult cows have 32 teeth. On the bottom, they have eight incisors in the front and six molars on each side in the back. On top, a cow has six molars at the back on each side, with the tough dental pad in between at the front.

Calves are born with temporary incisors, but within a month, the rest of the incisors develop. From age two years on, the permanent adult teeth erupt and develop and replace the baby teeth. By age three, cows have permanent teeth.

What Kinds of Teeth Do Cows Have?

Cows have several kinds of teeth.

• Incisors—Incisors are sharp flat teeth made for biting. They’re shaped like chisels. In cows, incisors are for biting off the grass. Cows have eight incisors on the bottom at the front. These incisors are used for biting grass, not people or other animals. Cows can’t really bite a person or animal because when a cow’s mouth closes, those bottom incisors meet up with the toothless dental pad on the top jaw and not another set of biting incisors like in dogs or cats.
• Canines—Cows also have two bottom canine teeth, but these canine teeth aren’t pointed like a dogs’ canine teeth. It’s hard to visually identify the canines in a cow because they look just like the incisors.
• Molars—Cows have 24 molars that are meant for grinding and crushing. They’re located at the back of the jaws and are instrumental when a cow chews its cud. To grind and crush, cows chew their food from side to side.

How to Estimate a Cow’s Age by Its Teeth

Good birth records offer the best proof of a cow’s age. Without birth records, farmers and veterinarians often turn to examine the cow’s teeth to determine its age. Some question the reliability of this method because forage type can affect tooth wear and tear, as discussed in the second bullet that follows.

So, how do you estimate a cow’s age by its teeth?

• Dentition—Dentition is the order in which teeth develop in the mouth. If you know the order and can identify the particular teeth, you’ll be able to estimate the calf, heifer, or cow’s age more closely. Calves develop 20 baby teeth that are smaller and whiter than adult teeth. These temporary teeth fall out and are replaced by permanent teeth. Use the following chart as a general guide: Temporary or baby teeth:
  Birth—Temporary teeth partly erupted
  20 days—Incisors erupt
  30 days—Six temporary molars erupt
  6 months—Teeth are touching each other
  12 to 18 months—Calves and heifers have all of their temporary teeth
  Permanent teeth:
  1 to 1.5 years—Molars start to erupt
  1.25 to 2 years—Front two incisors (pincers) are in place
  1.5 years—Those incisors start to show wear
  2 to 3 years—Two more incisors and more molars develop
  3.5 years—Those incisors start to show wear
  4 years—Two more incisors develop
  5 years—Two corner incisors develop
  6+ years—All teeth in place
  12+ years—Signs of missing teeth
• Wear and tooth loss: To estimate a cow’s age by its teeth, one must also look at the condition of the teeth. Years of biting and grinding during eating wear teeth down. The degree of wear becomes only a clue in determining an approximate age because other factors, such as the type of forage, comes into play. As for forage and grazing conditions, cow’s teeth can wear faster if they have been grazing on sandy or rocky pastures and not as fast if grazing on irrigated pastures. Or if they need to pull at shorter grass continually. Generally, at six years old, cow incisors begin to wear below the grinders, just starting to show wear. At eight years old, the cow’s grinders are showing significant wear. Gaps between teeth tend to widen with age, and the necks of teeth become narrower. In addition, teeth become flatter (peg teeth), and, sometimes, the roots may become exposed.

Related questions

Can a Cow Bite You? Cows cannot bite because they don’t have top teeth. The dental pad makes it so that a cow can only gum you even if it tried. Cows don’t bite for any reason naturally, even during eating. So, cows are also very unlikely to attempt to bite a person or animal. It would not occur to a cow to even try and bite because cows use their tongue to pull grass and other food into their mouths. They simply don’t have the experience to bite, so that it wouldn’t be a natural response. Instead, a cow would likely head butt, kick, run at, use their horns, or another method of defense if they felt threatened. Cows have three types of teeth, including molars, premolars, and incisors. Their incisors are used for chewing grass, along with their molars and premolars.

Are Calves Born With Teeth? Baby calves are born with temporary teeth, called milk teeth. Milk teeth are the equivalent of baby teeth in calves and only last for about 18 months. When the cow is around 18-24 months, the first set of permanent teeth, lower incisors called pincers, will come in and push the milk teeth out. For each of the next 3-4 years, the milk teeth next to the permanent teeth will fall out, and new incisors will replace them until the cow has all permanent teeth and no milk teeth.

Additional Resources

Microsoft Word – TeethCattleAge_Aug2013 (msstate.edu)

What Is Meant by “Solid Mouth” or “Broken Mouth” Cows?

How Much Does A Cow Cost To Buy