EUEEAU OF ANIMAL INDUSTRY. 121 



BLACKLEG VACCINE. 



During the fiscal year 3,454,628 doses of blackleg vaccine were 

 distributed to stock raisers and farmers. This is approximately 45 

 per cent more than was distributed during the fiscal year 1914. This 

 increase, however, does not indicate that the disease is on the in- 

 crease, but rather that stockmen in blackleg districts who havenot 

 previously vaccinated their animals are recognizing the practicability 

 and value of vaccination. 



INVESTIGATION OF POULTRY DISEASES. 



During the year a large number of diseased domesticated birds or 

 their carcasses were received from various States for examination 

 in the pathological labora.tory, and an increased volume of corre- 

 spondence asking for advice and information relative to poultry 

 diseases was received. 



The apparent increase in the spread of bacillary white diarrhea 

 of young chicks caused a line of research to be started for the purpose 

 of developing biologic agents to combat its ravages. Research work 

 was also begun on the problem of developing a method for immuniz- 

 ing fowls against fowl cholera. 



Special investigations to determine the therapeutic value of pro- 

 prietary medicines were conducted in cooperation with the Bureau of 

 Chemistry under the food and drugs act. 



Some tests were made to determine the possibility of using products 

 elaborated by Bacterium 'puUorum in culture to detect infection 

 caused by that organism in fowls, in a manner similar to the in- 

 tradermal tuberculin test. The test was applied to fowls artificially 

 infected with Bacterium puUorum and to healthy control birds. The 

 results were to some extent discordant, but were such as to warrant 

 continuing the work. 



FOWL TICKS AND SPIEOCHETOSIS. 



In many countries the fowl 'tick Arr/as miniatus, besides being a 

 serious parasite of fowls, transmits the blood parasite Spirochceta 

 gaUinamm, which causes a disease of fowls known as spirochetosis. 

 The presence of fowl ticks in the United States, in southern and 

 western Texas and in a belt of territory along the southern and west- 

 ern border to a point north of San Francisco, Cal., raised the ques- 

 tion of the existence of spirochetosis among fowls in that region. 

 Twenty-four lots of ticks were subjected to examination and used 

 in various ways in the attempt to induce spirochetosis in young 

 chickens bred in the vicinity of Washington. In no case was dis- 

 ease produced. Microscopic examination of the blood of fowls gave 

 negative results. The work is being continued with ticks and fowls 

 from flocks where there is definite suspicion of the existence of 

 spirochetosis. 



COOPERATIVE WORK ON POULTRY DISEASES IN CALIFORNIA. 



Cooperative work has been conducted with the University of Cali- 

 fornia in the investigation of poultry diseases. The main problem 

 under investigation has been the clearing up of the confusion regard- 



