PRINCIPLES OF SWINE BREEDING 43 



same breed a pure-bred boar should be selected to mate 

 with these sows in order to secure a uniform lot of pigs. 

 While uniformity of itself may possess no real value, it 

 is one of the best paying investments to be made, for it 

 generally costs little or nothing and the market pays well 

 for it. The selection of the boar should be most carefully 

 made, regardless of the ultimate object of the breeding. 

 If grade sows are used and pork is to be produced, the 

 aim should be to continue the grading up from year to 

 year and from boar to boar. Such breeding practice con- 

 tinued through but a few years will give one a herd of 

 grade animals comparing quite favorably with pure breds 

 so far as uniformity of product and resultant offspring 

 are concerned. Breeding for pork production alone has 

 several distinct advantages over breeding for breeding 

 purposes, and not the least among these advantages is 

 the fact that in the pork-producing herd it is necessary to 

 keep the breeding animals in as high condition as in the 

 case of the pure-bred herd. 



Breeding condition. While we must not forget the 

 necessity of keeping our breeding animal in high condi- 

 tion, we must recognize the incompatibility of too high a 

 condition with the best of breeding qualities. The best 

 results are obtained when the animals are neither too fat 

 nor too lean, but when they are in what might be con- 

 sidered the most healthy condition. 



The results of too high condition. This danger of too 

 high a condition in breeding animals is already well 

 known. As to the causes, there may be several, but in 

 the cases of the females it is safe to assume that the large 

 quantities of fat deposited around the internal repro- 

 ductive organs do not make for the best breeding quali- 



