200 ILLINOIS DAIRYMEN'S ASSOCIATION. 



ing usually referring to merely one act or single instance of 

 bringing together blood of close relationship. It was necessary 

 to do this in the early clays of the modern improved system of 

 breeding in order to preserve the most desirable types and fix 

 them into a permanent form that would enable them to be trans- 

 mitted with a degree of certainty. Thus the office of close 

 breeding in those days was to intensify certain desirable charac- 

 ters and hasten the development of a large number of superior 

 animals of an improved type. 



With our principal breeds thoroughly established as they 

 are today, there is not the necessity for close breeding there was 

 one hundred and fifty years ago, nor can it be practiced as it was 

 then. The longer a breed exists the more intensified its blood 

 becomes and the more danger there is of some of the evils which 

 ar sure to follow where close breeding is practiced to a greater or 

 less extent. 



As stated before, the office of close breeding seems to be to 

 intensify the transmission of characters. The chief difficulty 

 is that weaknesses, such as tendencies to barrenness, impotence, 

 reduced fecundity, and diseases are as ape to be intensified as are 

 some of the strong features. It is not always possible to know 

 the exact tendencies of an animal and in this respect one takes 

 chances in attempting to intensify what may seem strong and de- 

 sirable characters. The writer has observed in several instances 

 where mating two closely related animals, apparently strong and 

 robust, resulted in a marked reduction of size and strength on 

 the part of the offspring, showing a tendency toward delicacy 

 which did not warrant a second attempt. On the other hand, 

 remarkable animals are known which are the result of very close 

 breeding. Those who argue strongly against this system of 

 breeding make the statement that where one superior animal is 

 produced as the result of close breeding, many inferior ones are 

 produced. It is difficult to collect data which will vouch for such 

 statements, for the reason that breeders are very loath to report 

 failures in their operations, and do not usually make known the 

 sacrifices necessary for securing a few excellent individuals. 



