evaluating teeth to determine
age of sheep
The age of a sheep can be estimated by examining its teeth. Sheep have no upper incisor teeth. A lamb is born with a full set of temporary incisors, or “milk teeth”, on the lower jaw. As the lamb ages, these are replaced with adult teeth at the rate of one set of permanent incisors per year from one to four years of age. After that, the teeth begin to spread and show wear, and some teeth can be lost. Below are illustrations of teeth for different ages of sheep.
90 DAY OLD LAMB Incisors of a 90 day old lamb referred to as lamb teeth or milk teeth. Lambs are often evaluated at shows for a “lamb mouth” which is free of any permanent teeth.
1 YEAR OLD LAMB All of the “lambs teeth” are still intact, but the incisors have spread and are approaching yearling status.
OVER 1 YEAR OLD LAMB First pair of permanents erupted and 3 pairs of lamb teeth. The first set of incisor teeth have erupted indicating that the sheep is over a year old and will not qualify to show in a lamb class as such.
1 YEAR OLD SHEEP One pair of permanents in wear. This would be interpreted as a one year old sheep (one set of permanent incisors).
2 YEAR OLD SHEEP Two pair of permanents and two pair of lambs Teeth. This would be interpreted as a two year old sheep (two sets of permanent incisors).
3 YEAR OLD SHEEP Mouth of the “three year” old. This would be interpreted as a three year old sheep (three sets of permanent incisors).
4 YEAR OLD SHEEP Full mouth - 8 permanents. This would be interpreted as a four year old sheep (4 sets of permanent incisors).
5 YEAR OLD SHEEP “Spreader”. These teeth are showing age and would indicate an age over five years of age.
BROKEN MOUTH Broken mouth. Teeth in this condition would be a reason to have culled a sheep as its ability to graze and thrive will be compromised.
illustrations by cali roberson
DETERMINATION OF SHEEP AGE FROM THE DENTAL IMAGES ABOVE ARE NOT EXACT. SHEEP MATURE AT DIFFERENT RATES BUT THESE ARE GOOD GUIDELINES FROM WHICH TO EVALUATE THE AGE OF A SHEEP AS IT PERTAINS TO THEIR STAGE OF PRODUCTIVITY.
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