Tuberculosis in Live Stock. 
19 
It is important to eradicate tuberculosis from pure-bred herds 
of cattle at the earliest possible date because the spread of the disease 
is greater among such animals than among grade cattle. The reason 
is plain; pure-bred animals are shipped extensively to every part of 
the United States for breeding purposes. A pure-bred bull or cow 
may be shipped from Maine to Texas, or from the State of Wash¬ 
ington to Florida. If it is diseased and is introduced into a healthy 
herd, it not only fails to fulfill the purpose for which it was intended— 
the upbreeding of the herd—but it actually causes heavy damage 
by spreading the disease to healthy animals. 
Fig. 11.—This Hereford herd was freed from tuberculosis within 3 years. The first test, in 1916, showed 
the herd to be 10 per cent tuberculous. The reactors were removed and in 1918 all the 62 animals in the 
herd were found to be healthy. 
ACCREDITED-HERD OR HONOR-ROLL PLAN. 
The breeders of pure-bred registered cattle fully appreciated the 
above-mentioned fact when, together with the live-stock sanitary 
officials of practically all the States, they adopted what is known 
as the accredited-herd plan, the principles of which are that herds 
found to be free from tuberculosis on two successive annual tests 
are placed on the Honor Roll, and a certificate is given to the owner 
by the State and the Federal Government. The certificate entitles 
animals of that herd to be shipped interstate without further tuber¬ 
culin testing for a period of one year. This plan is becoming well 
known to breeders throughout the United States. The progress of the 
accredited-herd plan is given in Table 2. 
The methods of eradicating tuberculosis from grade herds are, 
of course, the same as for pure breds. No owner can rest assured 
that his herd is free from tuberculosis unless it has been properly 
