298 TUBERCULOSIS 
not be worn in the shed occupied by the healthy animals. He 
must remove all calves from the infected herd a few days after birth 
and bring them up on the milk of the healthy herd alone. The 
healthy herd must be tested every six months or so, and if any 
show reaction they must at once be removed from the rest. The 
tuberculous herd may be kept and milked, but the milk should be 
sterilized. By keeping up this procedure for a few years, it is 
possible to eliminate the infected animals and have left a herd of 
healthy animals. 
4. A still more recent plan has been widely adopted in Ger- 
many and seems at present to offer the simplest and most hopeful 
solution. It consists in separating all calves, as soon as born, from 
their mothers, and rearing them separately from the rest of the herd. 
Tuberculosis is not hereditary, and the calves of tuberculous 
mothers are, when born, free from the disease (except in rare 
instances). If, therefore, they are at once separated from their 
mothers, brought up on pasteurized milk, and not allowed any pos- 
sible contact with the other animals, they may be reared free from 
the disease, becoming in a few years a herd of healthy cattle, and 
if they are guarded from outside sources of contamination they will 
continue to be free from the disease. Meantime the animals in 
the infected herd, whose milk may be used if thoroughly pasteur- 
ized, may be slowly disposed of, while the healthy, growing herd 
gradually replaces them with the smallest possible loss to their 
owner. Of course the healthy animals must not be allowed to 
enter the quarters formerly occupied by the diseased herd until 
there has been a thorough disinfection of the premises. 
Which of these methods of procedure it is best to adopt depends 
upon circumstances. Ifaman has only a small number of animals 
and only one or two of them are tuberculous, his simplest plan will 
be to slaughter the reacting animals at once. If his herd is a’ 
large one, it is best to build up a healthy herd by one of the meth- 
ods outlined. He must remember that a single tuberculous animal 
is a menace to his entire herd and he should begin his fight against 
