24 BULLETIN 593, U. S. DEPARTMENT OF AGRICULTURE. 
full set of permanent incisors will indicate that the sheep is at least 
four years old. If the sheep are kept in high condition, as show sheep 
often are, the process of replacing the milk teeth with the permanent 
‘ones will be hastened; on the contrary, a lack of proper feed will 
retard the process. Although it is not possible to tell the age of sheep 
by the teeth with accuracy after they have a full set, it may be de- 
termined roughly by the condition of the teeth. As the sheep gets 
Fig. 17.—Noting width of rump. 
older the teeth are worn down. As the teeth may become broken 
and lost, thus affecting the ability of the sheep to feed, all older sheep 
should be examined to note if the teeth are in working condition. 
In examining the mouths of sheep one should be patient and not be 
rough in the exertion of force. With one hand holding the head 
against the thigh to steady it, the lps should be parted with the 
first two fingers of the other hand (fig. 22). If this is done quietly 
and gently, there will be little difficulty in exposing the teeth. 
