-Breeding 449 



an important vehicle, therefore, in obtaining concen- 

 tration of blood and fixity of type. The extensive prac- 

 tice of in-breeding in the early formation of our present 

 breeds was justified by this fact. 



2. When in-breeding is practiced promiscuously, it 

 almost inevitably results in reduced vigor and impaired 

 fertility. The closer the relationship, the quicker and 

 more certain will these results follow. Even when used 

 mildly and with the greatest skill and caution, the prob- 

 abilities are that some weakness will ultimately result if 

 long continued. 



3. The conditions are not existent to-day which justify 

 in-breeding as they were during the formative period of 

 the breeds' development. Then there was dissimilarity 

 of type and ancestry, while now there is uniformity of 

 type and a breed or blood relationship more or less close 

 among all the individuals of a breed. The first breeders 

 often could not find as good stock outside their own herds 

 as they had in them, and hence used sires of their own 

 breeding. Now, the opportunity for selection is much 

 broader and the necessity for using a closely related 

 sire is practically eliminated. Furthermore, present-day 

 stock is probably less immune from the possible evils of 

 in-breeding than the foundation stocks, because a certain 

 amount of in-breeding has already been practiced in 

 every breed. 



PRINCIPLES IN THE SELECTION OF BREEDING STOCK 



There are three ways of judging an animal's ability 

 as a breeder : first, by his individuality ; second, by his 

 pedigree or breeding ; and third, by his actual performance 

 record as a breeder. 



