72 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



The county-control investigations haA-e served a useful purpose in 

 demonstrating what may be accomplished in that way, and appar- 

 ently have stimulated activities in a number of the principal hog- 

 raising States. The plan, however, as carried out in an experimental 

 way, with the use of free serum administered by bureau veterina- 

 rians, is impracticable and too expensive for extending the work to 

 any great portion of even one State, and has therefore been discon- 

 tinued. 



The educational and demonstrational work was continued in 10 

 States (Alabama, Arkansas, California, Florida, Georgia. Iowa, 

 North Carolina. Oklahoma, Texas, and Virginia) in collaboration 

 with the States Relations Service of this department and the exten- 

 sion departments of the State agricultural colleges. The activities 

 may be summarized as follows: Fourteen hundred and sixty-six ad- 

 dresses, 402 of which were illustrated with stereopticon views, were 

 made at meetings attended by 138,746 people. Four hundred and 

 sixty-six demonstrations of preventive treatment were made, 335 

 with the use of serum alone and 124 with simultaneous inocula- 

 tion, 10,933 hogs being treated, with an attendance of 12,188 persons. 

 Eighteen hundred and seventy visits were made to farms for the 

 purpose of diagnosing hog cholera or observing conditions and giv- 

 ing advice, and 15,812 farmers and hog raisers were personally inter- 

 viewed. Individual instruction in properly administering the pre- 

 ventive serum treatment was given to 1,336 persons, including 164 

 county agents, 67 practicing veterinarians, and 1,074 hog owners. 



During the coming fiscal }^ear hog-cholera work in the field will 

 be principally regulatory in character, looking to the control of the 

 disease in selected districts, in States where suitable arrangements 

 can be made for cooperation with State authorities charged with the 

 enforcement of quarantine and sanitary measures or with other 

 officials engaged in the control of hog cholera. In States where 

 satisfactory arrangements can not be made for intensive regulatory 

 work some education and demonstrational work will be continued in 

 a modified form. It is believed, however, that the farmers through- 

 out the principal hog-raising districts are already familiar with the 

 possibilities of reducing losses by the preventive serum treatment, 

 and that very little further work of this character should be required. 



A new process for producing clear, sterilized antihog-cholera 

 serum has been worked out by Dorset and Henley, of the Biochemic 

 Division. This and other research work relating to hog cholera is 

 reported under the heading of that division. 



Sensitized virus, according to the principle first used by Besredka 

 for typhoid fever and by Marie and Remlinger for rabies, has been 

 used in vaccination against hog cholera by Duval and Couret. of 

 Tulane University, who claim to have obtained highly successful 

 results by their process. This method is still in the experimental 

 stage, and the several tests supervised by the Bureau of Animal In- 

 dustry have not given satisfactory results. 



THE TUBERCULOSIS PROBLEM. 



A practicable and effective method of eradicating tuberculosis of 

 live stock is greatly to be desired. This is a problem to which the 



