24 SOUTHERN PORK PRODUCTION 



Cross-breeding. Strictly speaking, by cross-breeding 

 we refer to the crossing of two different breeds, yet from 

 the standpoint of breeding it may refer to the crossing of 

 different types or strains. This crossing is often made 

 use of in our breeding operations where increased size, 



Successful swine breeding is dependent on the reproductive 

 process. Courtesy Joe R. Martin of Georgia. 



vigor, thrift and fertility are sought. Many highly bred 

 females will not conceive to their kind, and a different 

 strain must be used. While, of course, there are advan- 

 tages to be gained by cross-breeding, it is not without 

 disadvantages. It always results in more or less in- 

 stability, and one cannot foretell with what success the 

 cross is being made. For this reason it is better to always 

 make moderate crosses only, for radical crosses more 

 often result unsatisfactorily, the instability of type 

 probably running several generations before being 

 re-established. 



The reproductive process. In order that a breeder may 

 carry on his work with intelligence, he should become 



