228 IOWA DEPARTMENT OF AGRICULTURE. 



a deeper interest. Tuberculosis in man, tuberculosis in animals, no matter 

 whether swine, cattle or fish or birds, is practically the same. It is sim- 

 ply a modification of the tubercular germ or adapting itself to a different 

 animal or individual just like the seeds that you take from one section of 

 Iowa to another. They get acclimated, grow and develop and get so they 

 will grow in that part of the State; and so it is with the tubercular germ. 

 The different classes of tubercular germs simply depend for their exist- 

 ence and change in shape upon the environment in which they grow. 

 Whether they are more deadly or less deadly depends upon the tissue in 

 which they grow. The different germs as they grow and develop affect ani- 

 mal tissue. In taking up the subject of tuberculosis in swine it will be 

 necessary to consider tuberculosis in general as it concerns cattle. Tuber- 

 culosis by the ingestment of food, sputum, excreta — the common cause of 

 tuberculosis in swine — the different conditions or situations or general 

 influences have all to do with the production of tuberculosis, no matter 

 whether in the human family or in the animal kingdom, and in order to 

 take it up and discuss it I simply follow notes that I have made. 



Now, as to tuberculosis in cattle. We know that we have a great deal 

 of tuberculosis in cattle. We have a lot of tuberculosis in cattle in Iowa 

 because we have a lot of cattle, and we have a lot of well bred cattle, and 

 cattle that are well bred are usually well cared for. They are kept inside, 

 kept tied up possibly a good part of the time, and animals that are kept 

 under these influences develop tuberculosis to a greater extent than a herd 

 of animals turned out in pasture or in open lots. There are many reasons 

 why animals kept together will become infected, or where one animal in a 

 stall will infect animals around. One reason is that where we have tuber- 

 culosis of the glands of the throat the cattle cough, the matter drops in 

 the feeding box, then it is pushed along the trough and the different cattle 

 along the trough become infected as a result. Animals kept in single 

 stalls with high partitions will affect animals on either side, but not those 

 in the stanchions kept away. There is a difference in susceptibility. Some 

 individuals will contract tuberculosis while others of the same family 

 under the same conditions will not. It is not hereditary. Recent experi- 

 ments extending back for ten years have demonstrated this. We some- 

 times find tuberculosis in the offspring where we did not find it in the 

 parent. The inherited tendency to become affected is the reason why one 

 herd of cattle will get it or one strain of cattle and transmit the same 

 tendency. The same quality that existed in the tissue affect the general 

 conformation of an individual as the polled condition in the Angus or in 

 the Galloway. There is a certain property that the tissue has of taking up 

 germ life and giving it life and existence. You will find the tendency 

 in certain individuals of a family. That individual probably is more sus- 

 ceptible to scarlet fever or some other disease. That is simply the ten- 

 dency that exists on the part of the animal body to take on these germs 

 and become infected. There is a large percentage of human existence 

 that become infected with turbercular germs. It has been estimated that 

 probably 50 per cent of the individuals that reach manhood and woman- 

 hood that die from other causes have at some time been Infected with 

 tubercular germs. It is the same in cattle, and we have it so in all of 

 the warm blooded animals. 



