376 IOWA DEPARTMENT OF AGRICULTURE 
The following cuts show post mortem results on the Independence 
herd after the diseased animals had been slaughtered at Cedar Rapids. 
This post mortem was witnessed by members of the State Board of Con- 
trol and others interested in the test. 
The first picture shows a number of the animals after post mortem and 
ready for disposal. The latter gives a closer view of the tubercular lesions 
as existing in each of them. 
Experiments have proven that milk from a tubercular udder fed to 
calves has produced the disease in from one to ninety days. We also 
find that in Iowa the largest percentage of tubercular swine come from 
districts where the cattle are diseased, the infection coming through the 
faeces, milk or dead carcasses, for example: A case came under our ob- 
servation where a cow had died from tuberculosis. The carcass was 
drawn into the swine pen, giving the swine free access to the internal 
organs. The drove of swine were seventy-two in number, and were 
sold in about ninety days to a packing house where federal inspection 
was maintained. Upon being slaughtered every animal showed tubercular 
lesions, and twenty-two were consigned to the tank. 
Animals very rarely become diseased without coming in contact with 
infected ones, or by eating and drinking from the same boxes or troughs. 
It has also been demonstrated that tubercular mothers very rarely give 
birth to tubercular offspring. Almost every example proves conclusively 
that the greatest method of infection is through the digestive tract. 
Dr. H. E. Talbotj'^Assistant State Veterinarian, has compiled a report 
of intense interest, dealing with the testing of one thousand cattle, the 
animals being an average, and neither under suspicion nor within reach, 
so far as known, of the infection. Of this number, 306, or 30 3-5 per cent 
reacted, and 61 per cent of the entire herds were suspected cases. The 
306 animals found reacting were condemned, and were slaughtered under 
federal inspection, but one of the number being found free from tubercular 
lesions. There were seventy-six of the slaughtered animals put in tank- 
age as unfit for use. 
While this report of 1,000 animals comprises but approximately one- 
fourth of the number tested by us during 1908, this number has been sufii- 
cient to establish beyond any question of doubt the reliability of the 
tuberculin test. 
We have experimented with tuberculin upon animals having previously 
reacted to the test, and infected with tuberculosis, for the purpose of 
determining how often cattle would react. We will give one experiment, 
using the owner's name by his permission: 
W. F. Parks, Indianola, Iowa; dates, February 5 and 6, 1908; number 
tested, twenty-five, all being pure bred Short Horns; number reacting, 
thirteen. Of this number six were immediately slaughtered, the remain- 
ing seven being allowed to stay on the premises for the purpose or saving 
their calves. We were unable to give the exact dates of the subsequent 
tests, but can give them very closely. In about ninety days (May 1st) 
these seven cows were retested, only five reacting, no attention whatever 
being paid to advanced pregnancy, the majority of them having calved. 
One animal, however, which was due to calf in about ten days, failed to 
react. 
