1086 EXPERIMENT STATION RECORD. 



Sheep were found to be somewhat more susceptible than cattle, as 

 evidenced by the larger lesions and the permanence of the tuberculin 

 reaction. All three species were found to be highly susceptible to 

 cultures of bovine origin. In the case of cats, only two were tested. 

 The effects were about the same, being slight in either case. The sus- 

 ceptil)ility to tuberculosis produced by inoculation in the domestic 

 animals does not correspond strictly to the extent of the naturally 

 acquired disease. Among the other factors which may be important 

 in determining this matter, the author attributes weight to the T)ad 

 ventilation in sta})les. 



Tuberculous co"ws and the use of their milk in feeding calves, 

 C. S. Phelps {Connecticut Stows Sta. Rjjt. 1899, j^P- ^^0-167).— The 

 author continued experiments with -i cows upon which a report has 

 been previously noted (E. S. R., 11, pp. 890, 891). These cows had 

 been under observation for 3^ years. Detailed statistics concerning 

 the histor}^ of the cows and of the calves which were fed upon their 

 milk are presented in tabular form. One of these cows gave no reac- 

 tion to the tuberculin test since January, 1897, a period of 3i years. 

 The second cow responded to the test in December, 1899, bnt failed to 

 respond on March 20, 1900. The third cow showed a reaction in June, 

 1899, but did not respond when tested in December, 1899, and on 

 March 20, 1900. The fourth cow failed to respond to tests which were 

 given in the years 1899 and 1900. 



During a greater portion of the 3i years, the milk from the 4 tuber- 

 culous cows was fed to calves. In some cases the calves were fed until 

 they were a year or more of age; and in most of the experiments they 

 were confined in the same stable with the cows and exposed to the 

 contraction of tuberculosis by ordinary contagion. A detailed history 

 is given of each feeding experiment, the general results of which may 

 be summarized as follows: 



During the first 2 years only 1 secondary case of tul)erculosis devel- 

 oped. This case appeared about 25 months after the cows were pur- 

 chased. During this time 4 animals were fed from the milk of the 

 cows for periods ranging from 12 to 18 months. At the same time 

 the experimental calves were closely associated with the cows. The 

 experience of the first 2 years indicated, therefore, that when tuber- 

 culosis exists in a cow in its incipient stages, the liability of its trans- 

 mission by milk or otherwise to calves which are associated with the 

 cows is quite limited. During the succeeding year and a half different 

 results were obtained. From August, 15, 1898, to March 20, 1900, 

 5 animals were fed upon the milk of these c^Qws, and all 5 contracted 

 tuberculosis. Two of these cases developed i<i calves 3 months old, 

 and the other 3 in calves from 12 to 18 monthg; old. The ph3'sical con- 

 dition of the cows indicated that the disease had become much more 

 generalized, at least in 3 cases. 



