PRINCIPLES OF BREEDING 93 



served by breeding his descendants. It is possible 

 by this method to secure the highest percentage of 

 blood of an exceptional individual and to establish 

 a strain that will perpetuate desirable character- 

 istics. If persisted in, the outside blood disappears 

 and the pedigree is rapidly enriched. Inbred 

 animals are recognized as especially prepotent. 

 The disadvantages of inbreeding are that if an 

 animal possesses any undesirable characteristics, 

 these characteristics, of course, are apt to be mul- 

 tiplied in the descendants, for good as well as bad 

 features are transmitted. There have been numer- 

 ous failures of inbreeding and these have probably 

 overshadowed the advantages. A careful investi- 

 gation shows that inbreeding is not necessarily 

 harmful, if properly handled. If animals lacking 

 in vigor and low in fertility are excluded, the best 

 of results will ordinarily come from inbreeding. 

 Some of the very best and most successful live- 

 stock men in the United States have practiced in- 

 breeding, and are able to show, at this time, herds 

 and flocks in prize rings, successful at the heads of 

 herds, and approaching, in every way, the breeder's 

 ideal of profitable live stock. Vigor, of course, is 

 the first proposition and fertility is a close second. 

 If these two characteristics are looked out for, there 

 will be very little danger in inbreeding. It is a 

 rather risky proposition to recommend it indiscrim- 

 inately to the general farmer, but the principles are 

 perfectly plain, so that he can practice it with profit 

 just as well as his more specialized brother. 



IMPORTANCE OF PURE-BRED SIRE 



With these general principles of breeding 1 in 

 mind, is it not perfectly plain that it will never do 



