EXPERIMENTS WITH TUBERCULOUS COWS. * 185 
These tests would seem to show that as the disease becomes 
nore advanced in the cows their milk is more infectious, and 
there is danger to the health of other animals, both from the 
use of the infected milk and in association with the diseased 
animals. 
Judging from the results of the physical examination made 
early in May, 1900, and from the general condition of the 
cows, the disease was reaching its more advanced stages, in 
at least three of the cows, by the spring of r900. In May of 
that year it was decided to test the question of the infectious- 
ness of the milk of the tuberculous cows upon calves from the 
non-tuberculous cows when the calves were isolated at pasture. 
Three calves from the cows in the College herd were selected 
which were believed to be free from the disease. These calves 
were placed in a small pasture near the Station barn. Calf L 
was fed the milk of cow No. 1337; calf M was fed the milk of cow 
No 1341, and calf N the milk of cow No 1343. The milk was 
transferred to another lot of pails than those into which it was 
mnilked, and the attendant was instructed to change his outer 
garments before passing from the barn to the calf pasture, and 
all possible means were taken to prevent the transmission of 
the disease in any way except by the milk. The calves were 
tested with tuberculin May 24-25, about three weeks after the 
feeding period began, and again September 28-29, after having 
been fed over four and one-half months. None of the calves 
responded to either of these tests. The calves were not fed milk 
after the September test, but were kept at pasture until late ‘in 
the fall. They were then given the shelter of a shed separate 
from all other stock. Calf M was found to be ailing on No- 
vember 28 and died November 29. An examination by Dr. 
Mayo revealed a congested condition of the stomach, kidneys 
and bladder, indicating some form of poisoning. An examina- 
tion of the lungs also indicated tuberculosis as follows: ‘‘ Tu- 
berculous nodule in the right lung, calcified, and mediastinal 
lymphatic tuberculous.’’ During the winter the two other 
calves were kept in the basement of a barn separate from all 
other cattle. In February, 1901, these calves failed to respond 
to the tuberculin test, and in May were sent to pasture with 
some other stock. 
