188 



MANUAL OF FARM ANIMALS 



of the permanent teeth and their method of wearing are con- 

 sidered the most accurate means of estimating age among cattle, 



yet they_ are not absolutely accurate 

 nor are they as dependable as in 

 the horse. Teeth in cattle vary in 

 much the same manner as in the 

 horse. See page 8 for variation in 

 teeth among horses. 



As in the horse, there are two 

 sets of teeth, — first, the temporary 

 or milk teeth, and later the perma- 

 nent teeth. The latter differ from 

 the former in their greater size. 

 This replacement of the temporary 

 by the permanent is made neces- 

 sary by the increased size of the 

 jaw as the animal grows older. 



The calf is often born with the 

 central pair of milk teeth, and the 

 remaining pairs appear within the 

 first month after birth. The calf 

 is provided with four pairs of in- 

 cisor teeth. There are incisors 

 in the lower jaw only, the upper 

 being provided with a cartilaginous 

 pad. 



When the animal is approxi- 

 mately eighteen months of age, 

 the middle pair of milk teeth is replaced by permanent ones, 

 which are fully twice as broad as the milk teeth, hence easily 

 recognized (Fig. 67). ' The intervals between the appearance of 

 the succeeding pairs varies much according to the conditions, 

 but can be stated as approximately nine months, perhaps more 

 rather than less. In general the age of the animal at the time 



Fio. 67. — Cows' Teeth ar- 



BANGED ACCORDING TO Age. 



Lowest row represents a 15 

 months' old mouth, second 

 row 18 months', third row 27 

 months', fourth row 36 

 months', fifth row 45 months', 

 and the top row represents 

 the teeth of a ten-year-old 

 cow. — Wallace. 



