THE RESULTS OF SOME BOVINE TUBERCULOSIS 



INVESTIGATIONS AT THE UNIVERSITY FARM, 



DAVIS, CALIFORNIA. 



By C. M. Haring, D. V. M. 



Presented at the Second Annual Meeting of the Medical Milk Com- 

 missions of California, April 18, 1910. 



The results of certain investigations concerning bovine tubercu- 

 losis that have been carried on at the University of California Farm 

 for the past three years cover several subjects which it is impossible 

 to embody in a brief heading. They'may be stated as follows : 



(1) A test of von Behring's Bovovaccine. 



(2) Observations on the Spread of Bovine Tuberculosis Undei 

 Outdoor Conditions. 



(3) Retesting Recently Tuberculinized Cattle. 



(4) A Search for Tubercle Bacilli in the Circulating Blood of Re- 

 acting Cattle. 



(5) Result of the Introduction of Cultures of Virulent Tubercle 

 Bacilli into the Circulation. 



A preliminary report of this work has been given in a paper by 

 Haring, Sawyer and Morgan 1 and in a monograph by Sawyer. 2 

 The present paper is intended to embody the results of the investi- 

 gations previous to May 1, 1910. 



A Test of von Behring's Bovovaccine. 



In the spring of 1907 forty-five calves were secured for experi- 

 mental purposes. Twenty-two of these were treated with bovovac- 

 cine after the manner of von Behring and twenty-three were kept 

 as controls. Twenty-seven of the calves came from a dairy of 

 thirty cows which were proven to be non-reacting by two tuber- 

 culin tests. Eighteen came from a dairy of eighty-four cows, six- 

 teen of which reacted to tuberculin. Of the twenty-seven calves 

 from the non-reacting dairy herd thirteen were treated with bovo- 

 vaccine, and of the eighteen from the eighty-four cow dairy, nine 

 were so treated. 



Great care was taken to follow the method and technic prescribed 

 by von Behring. The instrument case recommended by the Mar- 

 burg Institute was secured and the technic of inoculation carefully 

 followed. I will not take the time to describe the procedure in de- 

 tail, as most of you are familiar with this and the requirements of 

 von Berding as to age, environment, and manner of raising the 

 calves. An assistant in the employ of the University was sent to 

 the dairies to superintend the feeding and care of the calves. In 

 Professor von Behring's circular of directions No. 5, as published by 



iHaring, C. M.; Sawyer, W. A., and Morgan, D. N., Bovine Tuberculosis 

 Investigations. Proceedings of the American Veterinary Medical Associa- 

 tion, Chicago, September, 1909, pp. 252-2CO. 



2 Sawyer, W. A., Tubercle Bacilli in the Blood. Archives of Internal 

 Medicine, December, 1909, Vol. iv., pp. 628-638. 



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