128 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



judicious use of all three methods. No general outline can 

 be given as to when all three tests should be employed ; the 

 matter should be left to the judgment of the veterinarian 

 under whose direction the work is carried on. 



Marking Animals for Identification. 



It is very important to mark properly all cattle which 

 react to the tuberculin test, so that they may be easily 

 identified as affected with tuberculosis. One method that 

 is quite generally used is that of branding, a letter "T" 

 about 2 inches high is branded on the lower jaw, or some- 

 times it is placed on other parts of the body where it can 

 be seen readily. In addition to the branding it is advisable 

 to take the reacting animals so that one may be identified 

 from another, and in that way the results of the post-mor- 

 tem examination can be connected up with the reporting of 

 the tuberculin tests. The tag is usually placed in the ear 

 of the animal and contains a serial number as well as the 

 word "Reactor." 



Another method that is sometimes used is the punching 

 of a letter "T" out of the ear, and it has been quite satis- 

 factory. 



The marking of cattle that have passed the tuberculin 

 test is a matter that is being handled in different ways 

 throughout the United States, and it is believed that the 

 present methods of marking will be improved. In some 

 cases a metal ear tag is used and in others certain marks of 

 identification are tattooed in the ear. Tattooing has an 

 advantage over the tagging in that it is less expensive and 

 probably more permanent. 



It is not often necessary to require special marks on 

 pure-bred registered cattle, as the owner usually has a 

 method of identification, and this method of marking can 

 be used in connection with the tuberculin test as a record; 

 but on grade animals it is desirable to use some system of 

 marking that will show that the cattle have been tested 

 and found apparently free from tuberculosis. 



A system of marking swine so that the origin of those 

 found to be tuberculous on post-mortem efiamination can 



