14 The Bulletin 



tact with hogs from adjoining farms. In this way the infection is often 

 spread from farm to farm. 



Visitors — Hog cholera infection can be carried on the shoes and 

 clothes of people. It is unsafe for any one to visit an infected herd and 

 return to their own or any other herd of hogs. 



Garbage — Uncooked garbage from hotels, restaurants or other sources 

 is dangerous. We know of no instance in this State where uncooked 

 garbage has been fed for any length of time where cholera did not develop. 

 Feed it only to imrauned hogs or have it thoroughly cooked. 



SUSCEPTIBILITY 



Young pigs and young shoats are more susceptible than older hogs, 

 but often we find the older hogs the first to succumb to the disease. 



As to the susceptibility of the different breeds, we do not believe there 

 is any difference. The "scrub" hog and "mule-footed hog" succumb to 

 the disease as readily as the pure breeds. 



MORTALITY 



The mortality will vary in different localities and on different farms. 

 When cholera first makes its appearance in a locality the per cent of 

 deaths, as a rule, is higher than it is at the end of the outbreak. The 

 same is also tnie in communities where cholera has appeared for a 

 number of years in succession. The per cent of losses Avill range around 

 fifty per cent in some localities; in others as high as ninety-five per cent. 

 This depends on the virulency of infection and the susceptibility of the 

 hogs. 



As a rule hogs recovering from cholera are greatly depreciated in value. 

 Unless the hogs are exceptionally valuable ones, it would be more econom- 

 ical to destroy and burn them when they have developed a well defined 

 case of cholera. 



THE SERUM PLA>T 



The State Department of Agriculture now owns and operates a modern 

 and well-equipped serum plant. The plant consists of a serum laboratory, 

 virus laboratory, virus hog house, hyper-immune hog house, and about 

 twelve acres of ground devoted to hog lots. The Legislature of 1915 

 appropriated $5,000 for the production of the serum and reduced the 

 price from one and a fourth cents per cubic centimeter to three-fourths 

 of a cent per cubic centimeter, thus reducing the cost of the scrum to 

 less than it cost to produce it. 



A]VTI-HOG ( IKM.KRA SERUM 



In order to make potent anti-hog cholera scrum, il is necessary to 

 select a hog that is "immune" to cholera. Tliis hog is one that has been 

 treated with serum and virus at least twenty-one days, or one that has 



