DETERMINING THE AGE OF ANIMALS 



189 



In determining the age of the diflfercnt domestic animals 

 by the development and appearance of the teeth, most of the 

 attention is given to the lower incisor teeth. Up to the fifth 

 year, the age of the horse or ox can 

 be easily determined by the emption 

 and replacement of the incisors. 



At one year of age the colt has 

 a fully developed set of temporary 

 incisors. The ruminant's incisors 

 at this age all show wear. 



The two-year-old colt shows a well- 

 worn set of incisor teeth, and the 

 ruminant at this age has replaced the 

 nippers or centrals. 



The third, fourth and fifth years 

 are indicated by the replacement of 

 the temporally nippers, dividers and 

 comers in the horse, and the first 

 and second dividers and corner teeth 

 in ruminants. 



In the horse the permanent nip- 

 pers are full growm and in wear at 

 three years of age; the permanent 

 dividers are full grown and in wear 

 at four years of age; and the per- 

 manent corners are full grown and in 

 wear at five years of age. The table 

 surfaces of tlie incisor teeth of a five- 

 year-old horse show different degrees 

 of wear. At this period in the ani- 

 mal's age, the nippers have been in wear two years, the dividers 

 one year, and the corners are beginning to show wear. In rumi- 

 nants, all of the chisel-shaped table surfaces of the incisors show 

 considerable wear when the animal is five years old. 



Fig. 52. — Longitudinal .section 

 of incisor tooth: (A) cup; (B) 

 cement; (C) enamel; (D) ivory; 

 and (E) pulp cavity. (After 

 Huidekoper.) 



