Sheep farmers commonly use a sheep’s upper incisor teeth to determine how old they are. When lambs are first born, you would think they wouldn’t have any teeth at all; but this is untrue. Lambs are born with 4 sets of two temporary incisors on their bottom jaw called “milk teeth”, which are used to grasp the mother’s nipple for nursing. Their top jaw is just a dental pad with no teeth.
As a lamb continues to grow, so do their teeth. After one year or so, their temporary central incisors are replaced by a pair of permanent ones. At two years old, the second pair of temporary incisors are replaced by permanent ones. Then, at 3 and 4 years old, the third and fourth pair of temporary incisor teeth are replaced by permanent sets. So when a sheep is 4 years old, it should have a full set of permanent adult teeth.
After 4 Years Old
Once sheep pass the age of four, their permanent incisors begin to gradually spread apart. They will also begin to show signs of wear and tear, and possible breakage. In fact, when ewes (female sheep) have lost a few teeth, they are referred to as “broken mouth” ewes. If a ewe has lost all of their teeth, they are called “gummers” in the industry.
A sheep without incisor teeth is not necessarily in bad shape. They can still survive since their molars are the teeth that do most of the work in terms of chewing. On the other hand, a lack of incisor teeth does make grazing more difficult for them. But with proper care and supervision, this issue can be easily managed.