Swine Growers' Session. 



107 



place in this old infectious blood. I deemed it important, however, 

 to test this preserve blood since in practical work in the field, it 

 is often inconvenient to obtain fresh infected blood each time it is 

 needed. Moreover the delay of a week or more in securing fresh 

 infection may at times prove a serious delay. In this lot, three 

 pigs were injected with 1 c. c. of the "preserved" infection and 

 five pigs received 2 c. c. No ill effects were observed from the 

 inoculation of the serum or from the preserved infectious blood, 

 in the different quantities mentioned, when the immunizing serum 

 and the infected blood were used simultaneously. To test the 

 virulence of the "diseased" blood, another pig was inoculated with' 

 2 c. c. of the same preserved infectious blood (without the simul- 

 taneous injection of the "protective serum"). This pig died 10 

 days later from an acute haemorrhagic type of cholera. 



Lot 3. Pigs 1 to 8 all "vaccinated" and severely exposed to hog cholera. None became sick. 



The vaccinated pigs which had also been injected with the 

 same diseased blood showed no signs of illness. On December 2, 

 our records show that all the vaccinated pigs of lot 3 have remained 

 in good health from date of inoculation, fifty-one days before. De- 

 cember 12, all the pigs of lot 3 were exposed to natural hog cholera 

 infection by putting in the same pen a pig that was suffering from 

 the disease. December 28th the sick pig mentioned died. The 

 autopsy showed the haemorrhagic type of hog cholera, complicated 

 with broncho pneumonia (swine plague). December 29, two more 

 sick pigs from an infected herd were placed in this pen. Both these 

 recovered. Up to January 24th, none of the vaccinated pigs had 

 shown any sign of illness. On this date two of the vaccinated pigs 

 of this lot were fed diseased viscera — spleen, liver, and intestines, 

 from pigs that had died from the natural attack of cholera. Jan- 



