30 
Fanners’ Bulletin 1069. 
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 identifica¬ 
tion, 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 examination can be learned would be 
very desirable, and some experimental work along this line is now 
being conducted by the bureau in cooperation with owners and pack- 
el's. The results so far obtained indicate that the tattooing of a 
number or some mark of identification into the skin of the hog is the 
most practicable method but of course it entails additional labor 
and expense which would amount to a great deal if carried on through¬ 
out the country. It is hoped a more practicable and economical 
means of marking swine for identification will be developed in the 
future, as much good in the campaign for the eradication of tubercu¬ 
losis in live stock can be accomplished in that way. 
Many shipments which contain tuberculous swine are traced back 
to the farm by a system of reports kept by the Bureau of Animal 
Industry. By developing the methods of tracing tuberculous cattle 
and swine from the abattoir back to the farm where they were raised, 
efforts can be directed in eradicating the disease from these herds. 
APPRAISEMENT AND INDEMNITY. 
In addition to the various benefits derived from eradicating tuber¬ 
culosis, provision for the appraisement of diseased cattle with indem¬ 
nity for those slaughtered is a further incentive. Federal legislation 
and supplementary laws in numerous States now divide the burden 
WHY THE TUBERCULIN TEST IS HARMLESS. 
Tuberculin contains only the sterilized products 
of the tubercle bacilli. It does not contain any 
living germ; therefore it is harmless to any animal 
whether healthy or diseased. 
Only diseased animals give typical reactions to 
the test. The test does not injure animals in a 
condition of advanced pregnancy, and will not 
cause them to react if they are free from disease. 
Likewise, it does not produce reactions in disease- 
free animals which have recently calved. 
