HOG CHOLERA AND MEAT INSPECTION 223 



lowing weaning of the pigs regardless of the time 

 of year that farrowing will occur. 



When the pigs are weaned too young "runts" 

 are common among them, and in waiting for the 

 animals to become of sufficient size to receive si- 

 multaneous treatment it is not uncommon for the 

 breeder to prolong to a dangerous degree the in- 

 terval between serum alone and simultaneous 

 treatments. The passive immunity due to the 

 former partially disappears, and hog cholera, fre- 

 quently of an atypical and subvirulent type, some- 

 times appears among them. Often this type of the 

 disease is not recognized as hog cholera. Pigs in 

 large herds require earlier serum alone treatment 

 and are more likely to require two treatments 

 prior to the final serum-virus administration than 

 are those in smaller herds. This is because of the 

 fact that in large herds the chances for infection 

 are so great that the virus of the disease must be 

 regarded as being continuously present. 



Pasture and abundant room for exercise are of 

 great benefit to young pigs that subsist on gar- 

 bage. There seems to be a general fear that pigs 

 will "run all the fat off them" if they are allowed 

 generous room for exercise. We have repeatedly 

 observed the effects of turning pigs from cramped 

 and dirty quarters into pastures or large enclos- 

 ures, and the change has always been in their 



