128 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



ties in the field. In Louisiana, South Dakota, New Mexico, and 

 West Virginia the efforts are principally educational in character. 

 The other States in which control work is being conducted are 

 Arkansas, Alabama, Arizona, Delaware, Idaho, Indiana, Illinois, 

 Iowa, Kentucky, Michigan, Mississippi, Montana, Missouri, Maryland, 

 Nebraska, North Carolina, North Dakota, South Carolina, Tennessee, 

 Texas, Virginia, and Wisconsin. 



The total number of veterinarians engaged in the work has varied 

 from 160 to 195. The number of investigations of reported out- 

 breaks during the year was 38,046. The number of visits and 

 interviews with farmers and stockmen was 371,792. The number of 

 hogs treated during the year in connection with the work by bureau 

 veterinarians, practicing veterinarians, and others cooperating was 

 over 5,000,000. 



The extension of the work involves the investigation of reported 

 outbreaks of hog cholera, supervising and assisting in the treat- 

 ment of infected herds, cleanmg and disinfecting premises, estab- 

 lishing quarantine when necessary, and giving instruction and advice 

 to farmers, stockmen, practicing veterinarians, and others concern- 

 ing methods of prevention, treatment, and control of cholera. 



DECREASE IN HOG LOSSES 



The losses of hogs for the year ending March 30, 1918, were reduced 

 to 3,002,018, as compared with 7,004,756 in 1914. These figures are 

 equivalent to a loss of 119.9 per 1,000 in 1914 and 42.1 per 1,000 

 in 1918. The latter figure represents the lowest mortality rate in 

 swine for 35 years, and present conditions as a whole point to a still 

 greater reduction, 



NCREASE IN STOCK ON FARMS 



An important phase of the work has been to assist in formulating 

 and applying State and Federal rules and regulations for the immu- 

 nization and handling at public stockyards of stocker hogs intended 

 for feeding purposes on farms, in order that they may be returned 

 to localities where feed is available without danger of spreading 

 infection. These animals are subject to reinspection from time to 

 time, thus assuring safety to the feeder while the hogs are being 

 finished for market. 



Taken altogether the hog-cholera control work has been the means 

 of adding many millions of pounds annually to the Nation's supply 

 of pork products and represents a saving many times greater than 

 the cost of the work. 



OFFICE OF VIRUS-SERUM CONTROL. 



The preparation and importation of viruses, serums, antitoxins, 

 etc., for the treatment of domestic animals are supervised and regu- 

 lated under the virus-serum act of 1913 through the Office of Virus- 

 Serum Control, in charge of H. J, Shore. At the close of the fiscal 

 year there were 82 firms licensed by the Secretary of Agriculture to 

 maintain establishments for the preparation of such products for 

 sale in interstate commerce. These licenses covered 141 different 

 products. During the year 13 licenses were canceled. An increased 



