284 IOWA DEPARTMENT OF AGRICULTURE 



SWINE TUBERCULOSIS AND HOW TO GET RID OF IT. 



BY JOHN E. MOHLEB AND HENBY J. WASHBUBN. 



U. S. Bureau of Animal Industry. 



In coming to Iowa to speak on matters pertaining to the hog industry, 

 it is certain that I shall address an audience composed of people who 

 feel an active, practical interest in the subject under consideration, for 

 our national agricultural statistics show that Iowa owns in round num- 

 bers 8,413,000 of these animals, or considerably more than one-seventh ot 

 the entire hog property of the United States. 



The money value of this immense number of pork producing animals 

 is given in the same report as $54,684,000. You will understand that this 

 valuation is one that was placed upon the animals by their owners with- 

 out any reference to the conditions that might be exposed a little later 

 in the packing house, when careful observation would no doubt prove that 

 the presence of tuberculosis in many of these animals had greatly re- 

 duced their actual worth. 



It is quite possible that many of the farmers who have sold tuberculous 

 hogs in your state have done so without suspecting that they were un- 

 sound, for few of these diseased hogs ever manifest the presence of 

 tuberculosis by outward symptoms when they left the farm. In fact, the 

 hogs that disclose the affection at the time of slaughter are frequently the 

 finest appearing animals in the drove when they are brought to the abat- 

 toir. Should indications of tuberculosis be present they will usually con- 

 sist of those marks of general unthriftiness that are also present in many 

 other diseases, and therefore do not afford any very definite indication 

 of the presence of tuberculosis. 



In the majority of cases no intimation of the presence of the disease 

 will be given until the animal is slaughtered, and the discovery of a num- 

 ber of tuberculous hogs in a drove of apparently prime, well-finished 

 animals is often the cause of great surprise and disappointment to their 

 owner, yot the lesions may be so extensive as to render the meat unfit 

 for food purposes. 



Knowing that thousands of hogs contract tuberculosis every year, the 

 ((uestion which becomes of paramount interest to us is. how do these 

 animals gain the germs which cause the development of the disease? 



We may arrange the causes under four headings: 



1. Returned products from creameries. 



2. Raw milk or hand separated milk from tuberculous cows. 



3. Feeding behind tuberculous cattle. 



4. Feeding tuberculous carcasses. 



Considering these .causes a little more carefully, we will find in regard 

 to the first that while many creameries receive milk that is free from 

 tubercle bacilli, there are others unfortunately, which receive milk every 

 day from one or more cows so affected with tuberculosis that they excrete 

 tubercle bacilli, and these virulent germs find their way in large num- 

 bers into the cans of separated milk which are returned to the farmers 

 from these creameries. In this way a single advanced case of tuberculo- 



