ILLINOIS DAIRYMEN'S ASSOCIATION. 199 



whose merits are never known and whom worth perhaps does not 

 entitle them to a place in any herd. The breeders of pure-bred 

 cattle needs to practice rigorous selection and most careful man- 

 agement in his operations to avoid the production of this poor 

 class of pure-bred animals. Too close breeding, mating animals 

 too closely related, is another source of poor individuals among 

 pure-bred or even grade animals. This leads to the discussion 

 of close breeding. 



Close Breeding. 



Can a bull be used on his own daughters? Is it a good 

 practice to use any sire on his own daughter ? Will there be any 

 harm in breeding the dam to her own son or mating own brother 

 and sister? To what extent can close breeding be practiced 

 without any injurious effects? These are inquiries which come 

 to our notice frequently and are discussed under the subject, 

 Among breeders who have been close observers and successful 

 in practical breeding operations there is much controversy regard- 

 ing the subject of close breeding, which in a general sense refers 

 to the mating of animals more or less closely related. The sub- 

 ject as yet has never been thoroughly worked out in a manner to 

 cause all authorities to agree as to just what extent or limit this 

 system of breeding can be practiced. No man practices it intel- 

 ligently without some question or doubt in his mind as to results. 

 This is true for the reason that disastrous results do often ac- 

 company the practice and in the human family we know that the 

 divine law forbids incestuous marriages which is another term 

 referring to the impropriety and unlawfulness of uniting blood 

 which is closely related. 



In the breeding and improvement of many or our best breeds 

 of live stock, it will have to be admitted, however, that many 

 good results have been achieved by close breeding for at least a 

 time. In the formation of breeds it was almost necessary for 

 breeders to practice in-breeding and in some instances to keep 

 it up for several successive generations, which in the true sense 

 was in-and-in-breeding, the terms in-breeding and inter-breed- 



