176 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



I said before, it cannot be recognized by any known physical 

 methods. 



Now all animals which respond to the tuberculin test are 

 not necessarily dangerous at the moment, for the tuberculin 

 test picks out these animals in the early stages, long before phy- 

 sical evidences are apparent and long before the animal itself is 

 actually giving off tuberculin. This test enables you to detect 

 those animals which six months from now are going to become 

 dangerous. Suppose it only told you the animals which are in 

 the advanced stage, it would be useless for us to cope with this 

 proposition. Due to the fact that the tuberculin test separates 

 one class from another it becomes possible for you to further 

 prevent the disease spreading in your herd. 



If you bring into your herd a pure bred sire which is af- 

 fected in the earlier stages, it is simply a question of time be- 

 fore that diseased animal imparts this disease to its fellows. If 

 those animals do not occupy the same stalls it would not be as 

 rapid as if they did. After the advanced stages the animals ad- 

 jacent will become most affected, by drinking out of a common 

 water trough, by licking each other in the pasture. Under such 

 conditions it will spread from one to another until a consider- 

 able number become affected. This is the experience of the 

 Wisconsin farmer. 



Some years ago one of our short course students went down 

 into the southern part of this state and hired to a man who had 

 one of the finest herds in the state. This young man said to this 

 farmer: "Have you ever tested your herd?" The farmer said: 

 ' k I do not believe in testing my herd ; it is one of these Tommy 

 Rot schemes and I do not take any stock in it." The young man 

 said: "I do: I have seen animals tested for tuberculosis and when 

 > they were killed they were found to be in a horrible state. I am 

 satisfied there is something in it. Will you let me test your 

 herd?" The farmer replied: <4 If you want to I will give you 

 your time and you can spend two days in making the test." He 

 performed the test in that herd and of the sixty in the herd 

 twelve responded. When he brought the record sheet to his 



