290 AGRICULTURE 



the disease just starting, others with it well along, and still 

 others in the last stages. Since tuberculosis is contagious, 

 it is evident that when it once gets started in a herd it is 

 hard to stamp out. 



The tuberculin test. It is impossible to make certain 

 of the presence or absence of tuberculosis in a herd by any 

 set of symptoms. The only sure way is by the tuberculin 

 test. This test is required by law of all dairy herds in a 

 number of states. Experts have shown that tuberculin, if 

 properly used, will reveal the presence of tuberculosis in at 

 least ninety-eight per cent, of the cases. 



Tuberculin is a fluid in which tubercle germs have been 

 grown, but from which they have all been removed. This 

 fluid is injected with a hypodermic needle under the skin 

 of all the animals of a herd which is being tested. It will 

 not injure well animals nor give them the disease. Animals 

 that have tuberculosis reveal this fact by a feverish condi- 

 tion which arises from eight to twelve hours after the tu- 

 berculin is administered. Well animals show no such re- 

 action. 



Suppressing tuberculosis in cattle. Little can be 

 done in the way of treatment to cure tuberculosis in cattle. 

 Those that have contracted it in a mild form often recover. 

 Animals found to be well advanced with the disease should 

 at once be slaughtered. All diseased stock should be sep- 

 arated from well animals, and kept in different barns and 

 pastures. 



The milk from mildly diseased cows may be used, pro- 

 viding it is first carefully pasteurised. To pasteurize milk, 

 it is kept at a temperature of one hundred and forty-nine 

 degrees for twenty minutes, or one hundred and seventy- 

 six degrees for five minutes. This heating is sufficient to 

 kill the germs of the tuberculosis. 



