102 SWINE 



breeding, but by many breeders it is not* considered to be 

 as good a practice as line breeding because there seems 

 to be a tendency toward greater variation. 



Line Breeding. — Line breeding consists in mating ani- 

 mals that are pure bred and of the same breed which are 

 bred along similar lines or of the same family. By many 

 breeders this is considered the best form of breeding. It 

 brings together animals that are similarly bred, and con- 

 sequently more or less similar in type. This then will 

 be more conducive to the establishment and develop- 

 ment of a particular type of swine than where out cross- 

 ing is practiced. 



Close Breeding. — This is one degree closer than line 

 breeding; that is, it consists in the mating of animals that 

 are more closely related, but still not close enough to be 

 considered in the next class, namely, inbreeding. This 

 method of breeding is successfully practiced by a great 

 many breeders. If the animals are properly selected so 

 that they have no weak points in common which may be 

 transmitted and fixed in the offspring, it is a good prac- 

 tice because it has a greater tendency to fix points, either 

 good or bad, than either out crossing or line breeding. If 

 the animals are so mated that they have only good points 

 in common, these will naturally be more readily trans- 

 mitted to and more permanently fixed in the offspring. 



Inbreeding. — Inbreeding involves the mating of parent 

 and offspring or brother and sister. This form of breed- 

 ing may be successful, and occasionally is successful, but 

 it is considered in general by the swine breeders of the 

 country as a poor practice. While experimental data on 

 this point are lacking, it is not definitely known just what 

 may be expected from such breeding operations. How- 

 ever, the general opinion among breeders is that inbreed- 



