500 IOWA DEPARTMENT OF AGRICULTURE 



of tuberculosis may be destroyed without taking away the benefits 

 that may still be derived from the balance of the herd. 



One fruitful source of infection is skimmed milk from cream- 

 eries. The enactment of a law in Iowa, in accordance with the 

 recommendations of this department, prohibiting the sale or trans- 

 portation of skim milk from creameries and elsewhere without 

 pasteurization, has protected patrons of Iowa creameries from 

 this source of danger. Hogs are regularly infected through the 

 feeding of skim milk containing bacilli. Hogs are highly susceptible 

 to infection, and, while the life of the hog is shorter and the elimin- 

 ation of the disease through the replenishing of the herd more 

 practicable, enormous losses are brought about through tubercular 

 infection of hogs. 



The accompanying cut shows a number of hogs found to be tu- 

 bercular on slaughter and upon investigation it was found that 

 they had been pastured with tubercular cattle. 



The two most fruitful sources of infection is the introduction 

 into the herd of infected animals, and the feeding of milk contain- 

 ing tubercular bacilli. Guard these avenues well, and you will be 

 comparatively safe, provided proper sanitary measures are taken, 

 and no infection already exists in the herd. Every animal intro- 

 duced into the herd should be submitted to the tuberculin test, 

 and all milk secured from sources not known to be free from infec- 

 tion should be pasteurized. 



According to the report of the United States Bureau of Animal 

 Industry, there is a general prevalence of tuberculosis among cattle- 

 throughout the country. To undertake its eradication summarily 

 would be a hopeless task. The report mentioned sets forth a plan 

 of small quarantine areas in localities where the disease is unusual- 

 ly prevalent, allowing cattle and hogs to be shipped out only when 

 tagged for identification. It is hoped that in this way the infor- 

 mation reported back to the localities from which the infected 

 animals have been shipped will enable such localities to stamp out 

 the disease, and the area may be gradually extended from time to 

 time as the work progresses. 



Much experimentation has been under way recently with a view 

 toward the discovery of a vaccine for the immunization of cattle 

 against tuberculosis, but as yet the method is impracticable, al- 

 though hopes are entertained for its ultimate perfection to a point 

 where it will be adapted to the conditions that prevail. 



