lid ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



um by which the disease has been conveyed from one ani- 

 mal to another. Calves contract tuberculosis by nursing, 

 even for a short time, cows whose udders are affected. 

 Calves also become infected frequently by drinking milk 

 from diseased cattle isolated from the main herd. To be 

 safe for feed, milk from such cows should first be heated to 

 a temperature of 145° F. and held there for at least 30 

 minutes, but as this method requires considerable attention 

 to assure proper heating, boiling for a few minutes is con- 

 sidered a better plan. 



How Swine May Become Infected. 



The tuberculous cow is not only a menace to other cat- 

 tle but is also the commonest source of infection to swine. 

 In some parts of the country, especially where there are 

 whole-milk creameries and skimming stations, feeding 

 mixed skim milk to swine is a common practice. In that 

 way the skim milk from one farm may be fed to hogs on 

 another. Thus it is possible that milk from a few tubercu- 

 lous cows may set up the infection among swine on many 

 farms. 



Milk is a good medium for the development of the 

 tubercle bacilli, and swine seem to be extremely susceptible 

 to tuberculosis. Numerous instances are on record, also, in 

 which the whole milk is separated on the farm, the cream 

 shipped, and the skim milk fed to swine. Consequently one 

 tuberculous animal that is passing the germs in the milk 

 secretions may give the disease to any or all of the animals 

 to which any of the milk is fed. Investigations made by the 

 Bureau of Animal Industry show that in practically every 

 instance where tuberculosis exists among cattle, and swine 

 are kept on the same farm, some of the latter are tubercu- 

 lous. Eradication of tuberculosis from cattle, it is believed, 

 will greatly reduce its prevalence among swine. 



Another common practice of feeding, especially in the 

 Corn Belt States, is to allow hogs to run with cattle in the 

 feed lots or pastures. If the cattle are tuberculous and the 

 feces contain the germs of tuberculosis, in all probability 

 the swine will contract the disease. Swine may contract 



