How to Tell the Age of a Cow From Her Teeth

A cow's market value is largely dependent on her age. If there are no records indicating when she was born -- which is generally the case with large beef herds in the West -- the best estimation of her age is calculated by examining her teeth. Teeth erupt in a sequential manner in the cow's mouth, providing a general idea of how hold she is by her dental pattern. This is the most useful for cattle who have been mostly grazed throughout their lives and not been fed rough feeds that hasten wear on the teeth.

Things You'll Need

  • Head shoot
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Instructions

    • 1

      Secure the cow in a head shoot. Take care not to get a finger or an arm pinched against the shoot by her thrashing head.

    • 2

      Force your hand into the farthest side of her mouth, where no teeth are present. She will not be able to bite you if you keep your hand there. Carefully pry her mouth open to examine her teeth.

    • 3

      Check that all 32 teeth are present. This means the animal is at least 12 months old and at least has all of its "milk teeth."

    • 4

      Observe how many permanent teeth are present. Permanent teeth are significantly larger and thicker than milk teeth. If the bottom two center permanent incisors are present, the cow is at least 15 months old. Note that a cow will never grow incisor teeth on her upper jaw, which is called the "dental pad" for its absence of teeth.

    • 5

      Check for the presence of the pair of permanent intermediate teeth, which are located on both sides of the central permanent incisors. If they are presence the cow will have four teeth on the bottom jaw that are much larger than the rest. She is at least 24 months old. She is at least 30 months old if six permanent incisors are showing.

    • 6

      Look for the presence of all eight permanent incisors, which indicate she is at least 39 months old. Once all of the teeth are present the rancher or veterinarian must gauge the cow's age by the amount of wear on the teeth. It becomes much harder to estimate age once a cow has all of her permanent incisors. Nonetheless, once a cow has reached four or five years old her market value has already significantly decreased.