74 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Reports from inspectors indicate that there has been a further 

 recmction since the last estimate. Stated in another way, the 

 country-wide death rate from ho^ cholera in 1917 was but 42 per 

 1,000, the lowest in 35 years and a wonderful contrast to the 144 

 per 1,000 m 1897 and 118 per 1,000 in 1914. 



The protective serum has been used at public stockyards during 

 the last year in a way to increase the output of pork. It often 

 happens that a farmer ships his hogs to market when they are 

 not ready for slaughter, because hog cholera has appeared in the 

 neighborhood, or for some other reason. Formerly it was customary 

 to slaughter all hogs promptly after their arrival at public stock- 

 yards, whether they were in fit condition for slaughter or not, since 

 such yards were usually infected with cholera, and there was danger 

 that if pigs were shipped from the yards to farms for further growth 

 and fattening they would soon contract the disease and die, besides 

 infecting other hogs on the farm. It is now the practice to treat 

 these immature pigs with serum in the stockyards and send them to 

 farms where they are fed and allowed to reach maturity and a proper 

 degree of fatness. After that they are shipped back to market and 

 yield many more pomids of pork and lard than if they had been 

 slaughtered in the first instance. This considerable saving has been 

 made possible by the bureau's supervision of the commercial ]:)repa- 

 ration of serum under the law, thus making available a sufficient 

 supply of reliable serum. Only serum produced by licensed estab- 

 lishments is used at the stockyards. 



Tuberculosis, the most widely distributed destructive disease that 

 now menaces the live-stock industry, recently has been niade a 

 special object of attack. In cooperation with State authorities and 

 live-stock owners a campaign has been undertaken in 40 States along 

 three lines — namely, the eradication of tuberculosis from herds of 

 pure-bred cattle, the eradication of tuberculosis from circumscribed 

 areas, and the eradication of tuberculosis from swine. In the begin- 

 ning the efforts are being concentrated on the first project, smce the 

 pure-bred herds are the foundation of our breeding stock. A plan 

 which was adopted in December, 1917, by the United States Live- 

 stock Sanitary Association and by representatives of breeders' asso- 

 ciations and approved by the Bureau of Animal Industry has been 

 put into operation with the cooperation of a large number of herd 

 owners. With the consent of owners, the herds are tested with 

 tuberculin, and any diseased animals found are removed and the 

 premises cleaned and disinfected. Subsequent tests are made at 

 proper intervals. By this means there is being established a list of 

 pure-bred herds from which persons may buy breeding stock with 

 reasonable assurance that it is free from tuberculosis. The first 

 accredited list, consisting of more than 200 names of owners of 

 herds of pure-bred cattle, representing tests made up to the end of 

 the fiscal year, has been compiled and printed for distribution to 

 breeders. The list also contains 900 additional herds that have 



Eassed one successful test, but they must pass another annual test 

 efore becoming accredited. 



Heavy losses of horses have resulted from influenza or shipping 

 fever, especially among animals collected and shipped for war pur- 

 poses. Since the United States entered the war, the bureau has 



