Swine Growers' Session. 



115 



at once in the fresh condition. As to the keeping qualities of the 

 serum, Dr. Dorset has informed me that he has had samples that 

 have retained potency for several months.* The main drawback 

 to the use of the hog as a supply animal, in addition to the incon- 

 venience of collecting the blood, is the difficulty of supplying large 

 quantities in case of great outbreaks of the disease, since only small 

 quantities of blood can be secured from the hog at one bleeding — 

 only from 300 to 500 c. c. can be secured at one time, and this is 

 only sufficient for fifteen or twenty hogs at a. minimum dose. If 

 our attempts to make the horse and ox serve as supply animals are 

 successful, the drawback mentioned will be overcome. But even 



Fig. 7. Drawing blood for inoculating purposes, Veterinary Department, Missouri Ex- 

 periment Station— Niles method. 



if these larger animals do not prove appropriate for supplying the 

 serum, great service can be done the breeders of pure bred swine 

 through the present method, since the serum appears to retain its 

 immunizing properties for a considerable time and can be collected 

 and stored up for use during the seasons when the cholera is not 

 so prevalent. It is the purpose of our own Experiment Station 

 and College to serve the swine breeders of the State to the fullest 

 extent possible along this line. Our conveniences for doing this 



•In the Rinderpast inoculations of cattle in South Africa, after which, this work on 

 the hogs is planned, Drs. Turner and Kolle had samples of serum that were effective two 

 and one-half and three years after they were collected . 



