Ageing cattle by their teeth

Age is an important part of livestock trading as many markets have age limits. The age of an animal can be determined by counting the number of permanent incisor teeth, and is the most common method of determining approximate age in live cattle. Note: MSA grading uses bone ossification, which is assessed on the carcase in the meat works. Obviously this method cannot be used on live animals.

Cattle, like many animals, start life with baby or milk teeth. From about two years of age these teeth are replaced with permanent teeth. Permanent teeth erupt in pairs starting with the centre pair. A tooth is considered to have ‘erupted’ when it has broken through the gum. A pair is considered to have ‘erupted’ when the first tooth of a given pair has broken through the gum.

A heifer with a row of small milk teeth on the bottom jaw — The bottom jaw of this heifer only has a row of small teeth, indicating that she is a ‘milk tooth’ animal; likely to be less than two years of age.

The age of an animal is often referred to by the number of permanent teeth. An animal with only milk teeth is called a ‘milk tooth’, an animal with two permanent teeth is a ‘2 tooth’ and so on until they have a full set of eight permanent teeth when they are said to be an ‘8 tooth’ or ‘full mouth’.

Four large teeth on the bottom jaw of the cow and a large lump on either side indicates that two additional teeth are coming through. — This is a 6 tooth animal. There are four obvious permanent teeth and two more erupting on either side, breaking the gum, making it a ‘6 tooth’. Note that you count the permanent teeth on the lower jaw. The upper jaw has no teeth – only a dental pad.

The range in age at teeth eruption varies enormously from beast to beast due to individuality, breed, nutrition and climatic influences. Cattle, such as British-bred cattle, that exhibit early sexual maturity (puberty) experience teeth eruption at younger ages than late maturing cattle, such as Brahman cross cattle.

A guide for estimating the age (in months) of cattle by dentition

Teeth	Breed	Average age at eruption (months)	Average age at eruption (months)
2 tooth	British cattle Brahman cross	24 26	21–27 23–29
4 tooth	British cattle Brahman cross	31 33	26–36 28–38
6 tooth	British cattle Brahman cross	38 41	32–44 35–47
8 tooth	British cattle Brahman cross	46 51	39–54 43–58