BUREAU OF ANIMAL INDUSTRY. 159 



other swine diseases. Kecommendations were made leading to a con- 

 siderable number of seizures of such so-called " cures." 



EXPERIMENT STATION. 



The character of the work of the Experiment Station at Bethesda, 

 Md., under Dr. E. C. Schroeder, superintendent, was similar to that 

 of previous years, and comprised independent investigations of in- 

 fectious diseases of domestic animals, investigations in cooperation 

 with other scientific divisions of the bureau, and the provision of 

 facilities for the other divisions to make investigations under normal 

 farm and field conditions. 



BOVINE INFECTIOUS ABORTION. 



Infectious abortion disease of cattle remained the subject of major 

 importance. The knowledge now available on the etiology of this 

 widespread and common evil seems adequate to serve as the basis for 

 control measures. Such measures have been formulated, and as their 

 practicability and efficiency should be tested on a larger scale than is 

 feasible with the small number of cattle at the station, the use of two 

 large, privately owned and maintained herds, one a beef and the 

 other a dairy herd, has been obtained for the purpose, without other 

 cost to the Government than the expenses incident to periodic inspec- 

 tions, the making of biological tests, and the necessary technical 

 laboratory work. 



It has been known for some time that the Bang abortion bacillus 

 may attack swine as well as cattle. During the year a number of 

 cultures of the bacillus obtained from outbreaks of abortion among 

 swine were studied and compared with cultures isolated from out- 

 breaks of abortion among cattle. The cultures from the two sources 

 are identical in some respects but different in others. Attempts to 

 infect swine with cultures from cattle have invariably failed, while 

 similar attempts with cultures from swine have been successful and 

 have caused actual abortions. The swine cultures are also more 

 pathogenic for guinea pigs than the bovine cultures. 



An investigation of commercial suspensions of abortion bacilli 

 showed that these preparations are often not what they are labeled 

 to be and that their use should be discountenanced. Further investi- 

 gations on the subject are now in progi-ess. For the time bein^f it 

 should be generally recognized that protective inoculation against 

 bovine infectious abortion has not passed the experimental stage. 



Investigations are now being made to determine whether the ex- 

 posure of infected herds of cattle, in which abortions have ceased to 

 occur, to strains of abortion bacilli from other herds may lead to a 

 recrudescence of abortions. While it is too early to draw conclusions 

 from this work, the indications are that the exposure of such an in- 

 fected herd to abortion bacilli derived from outbreaks of abortion 

 among swine may have serious consequences. 



TUBERCULOSIS. 



Investigations on tuberculosis have been continued. More work 

 has been done to perfect the method now in use to measure the purity 

 and potency of tuberculin sold under Government license for vet- 



