398 Types and Market Classes of Live Stock 



other than a good purebred boar should be used on any herd. In hogs, 

 as in other stock, the sire is at least half of the herd. 



The 1920 census reported that 3.4 per cent of the hogs in the 

 United States on January 1, 1920, Were registered purebreds. ^ 



The sow may be bred when 8 months old, farrowing her first litter 

 when 12 months old. If well fed and cared for, she will raise two litters 

 per year, though many breeders believe that better results are obtained 

 if the sow raises one litter per year, or at most three litters in two years. 

 The average duration of pregnancy in swine is 114 days. Boars 8 to 

 10 months old may be used on a few sows if they are well developed 

 for their age and well fed. A mature boar will breed one sow a day, 

 or from 30 to 40 sows during the breeding season. 



With no other kind of live stock is there practiced so much mixing 

 of breeds and cross breeding as in the breeding of hogs for the market. 

 It is very commonly believed that by crossing a boar of one breed 

 upon sows of another breed, more vigorous and growthy offspring will 

 result. While there is no serious criticism to be made against such a 

 method so far as the first cross is concerned, it invariably happens that 

 if this policy is followed up and further crossing and mixing is resorted 

 to, a variety of shapes and colors is presented that is most unattrac- 

 tive as compared with a bunch of hogs possessing good uniformity. 

 In the majority of cases it will be most profitable to pick out one of 

 the standard breeds of hogs and stick to that breed year after year. 

 If this is done there need be no lack of vigor in the offspring if the 

 parent stock is selected with due care as to constitution and vigor. 



1 Nearly 60 per cent of these were in the corn belt. The ten leading states in 

 numbers of registered purebred hogs, in order of rank, were Iowa, Illinois, Indiana, 

 Missouri, Nebraska, Minnesota, Ohio, South Dakota, Texas, and Kansas. 



