608 ANNUAL, REPORT OP THE Off. Doc. 



six that were vaccinated two were vaccinated twice, one was vacci- 

 nated four times, one five times, another five times, another six 

 times, and tlien in another lot, that is, of another series, killed about 

 the same time, one was vaccinated two times. The dose upon the 

 first vaccination was small, the second was larger. Another was 

 vaccinated ten times, the ten vaccinations being made for the pur- 

 pose of ascertaining whether by repeated vaccination and whether 

 by the use of very large doses any injury would come to the animal. 

 Well, all of these vaccinated animals of this one series and two of 

 the other had been in contact with tubercular cattle for more than 

 a year, and some of them almost two years, and all of them were 

 found to be in condition of absolute health. There was no sign 

 whatever of tuberculosis in any one of these animals. The three 

 controls of one series and the single control of the other series, mak- 

 ing four in all, that had been exposed to contact with the tubercu- 

 lar cattle for some length of time were all tubercular, three of them 

 to a very great degree, one of them rather slightly. In the last con- 

 trol there was a good deal of natural resistance and, although it 

 became infected, the disease was not widespread. 



Other systems of vaccination with other cultures have not been 

 so successful. I have not the figures here with regard to them, but 

 I don't think they are of special importance because some of the 

 cultures that w'e were using for the other series of vaccinations have 

 now been discarded for this purpose because we found those cul- 

 tures did not give satisfactory results. So that the general result 

 of the vaccination with certain tested cultures has been satisfactory. 

 The result with other cultures has not been satisfactory, so that it 

 is perfectly evident that a great deal depends on the culture that is 

 used; a great deal depends upon a thoroughness of the treatment 

 with which the vaccinations are made. We are now beginning, on 

 a small scale, to put this system of protection into practical use. 

 We are trying, in our own experimental herds, for instance, the 

 vaccination of calves as they are born; the calves from tubercular 

 cows, the calves from the vaccinated cows, and from unvaccinated 

 cows, are some of them vaccinated by different processes, and others 

 are left without vaccination, with a view of determining whether 

 calves if vaccinated and exposed constantly to disease may be grown 

 in health. We have some cattle now in such an experiment that were 

 born nearly a year ago. We have some a little more than a year 

 old that, so far, appear to have resisted infection, but whether they 

 will wholly resist infection or not can only be determined by the 

 slaughter and the careful post-mortem examination of these ani- 

 mals. So that I say that now any attempt to make a report on those 

 cattle would be entirely premature because one cannot safely draw 

 conclusions from their apparent condition during life. We must 

 wait until a post-mortem examination has been made. 



The use of vaccination in other herds, as I say, has been started. 

 We have begun to vaccinate young cattle in herds, in different 

 places, and some of this work was started some months ago, and, so 

 far, appears to have given very good results. That is to say, the cat- 

 tle have not been injured in the slightest degree by the vaccination. 

 They have grown as well as unvaccinated cattle; they have had no 

 backset. No unthriftiness has been caused by the vaccination. 



