Assessing Age of Sheep
Always have the sheep sitting comfortably between your legs when conducting a physical exam. Once the sheep is restrained (see Sheep Restraint), the mouth of the sheep can be opened and the number and type of teeth can be used to determine the age and condition of the sheep.
- The age of the sheep can be determined by the number of teeth in their mouth
- Number, condition, and order of eruption of the permanent incisors of sheep are the main indicators of their age.
- The teeth of sheep are divided into two distinct sections: eight permanent incisors in the lower front jaw and twenty-four molars – six on each side of the upper and lower jaw.
- The upper part of the jaw at the front of the mouth is made of a fibrous pad – this is used to grind up food.
- The condition of teeth can give a good indication of the type of feed the sheep has access to: sheep that have been eating long, soft feed will continue to grow from lack of wear and remain in good condition. Sheep that have been eating where they have to graze close to the ground and the soil is sandy or gravelly, the teeth will be more worn down.
- After the 8 permanent incisors have appeared, the next stage is known as ‘broken mouth’
- If the sheep has very worn down teeth it may be harder for it to eat, so it may have to be given extra nutrients
|Age||Number/Type of Teeth|
|Lamb||8 milk teeth|
|1 Year||2 central incisors, 6 milk teeth|
|2 years||2 central incisors, 2 middle incisors, 4 milk teeth|
|3 years||2 central incisors, 2 middle incisors, 2 lateral incisors, 2 milk teeth|
|4 years||2 central incisors, 2 middle incisors, 2 lateral incisors, 2 corner incisors|
|5 years||All permanent incisors close together|
|6 years||Incisors begin spreading apart|
|7-8 years||Some incisors broken|
|10-12 years||All incisors missing|