320 PRINCIPLES OF BREEDING. 



seldom if ever useful breeders. This overloading with fat 

 seems to in some way have an undesirable influence on the 

 procreative organs. Animals which have been fitted for show 

 purposes should be gradually reduced in flesh by use of roots 

 and plenty of out-of-door exercise. In this way their usefulness 

 may be retained. Too close breeding, such as in-breeding or 

 in-and-in-breeding, is very likely to have an unfavorable in- 

 fluence on fecundity. This is very likely a provision of 

 nature so as to avoid the continued practice of too close breed- 

 ing, which has a tendency to concentrate the weak or unde- 

 sirable qualities in the offspring. This system also injures 

 the size and weakens the constitution of the animals. 



In the case of twin calves, where one is a male and the other 

 a female, the female seldom, if ever, breeds. She is called a 

 "free martin." The cause of this barrenness is supposed to 

 be due to the fact that the generative organs of the female 

 partake somewhat after those of the male. 



Fecundity to be secured in the highest degree in the breed- 

 ing of animals should be the aim of every breeder. To accom- 

 plish this end he must feed liberally on those feed stuffs most 

 nutritious, give the animals plenty of open air exercise, avoid 

 a high degree of flesh or fat in his breeding herd, and avoid 

 too close breeding of animals which are in any way related. 



