EXPERIMENT STATION BULLETINS. 607 



THE TRANSMISSION OF BAGT. ABORTUS (BANG) TO NEW BORN 

 CALVES THROUGH THE INGESTION OF MILK. 



BY I. F. HUDDLESON. 



Numerous investigations have demonstrated the infectiousness for 

 animals of milk containing pathogenic microorganisms. The occurrence 

 of Bacf. ahortiis in the milk from apparently normal cows has been 

 demonstrated by Schroeder and Cotton (1), Evans (2), and Cooledge 

 (3). The pathogenicity of milk containing Bact. abortus for guinea 

 pigs by the inoculation route has also been demonstrated by the above 

 investigators. The possibility of transmitting the infection to calves 

 through the ingestion of milk has not been conclusively demonstrated. 

 Williams (4) was the first investigator to publisli experimental data 

 concerning the transmission of Bact. abortus to calves through the in- 

 gestion of raw milk. He further associates the disease called infectious 

 abortion with white scours, acute or chronic vaginitis, pneumonia, and 

 matting of the hairy tufts about the orifice of the sheath and at the 

 lower commissure of the vulva of calves. His experimental data are as 

 yet inconclusive. 



Up to. the present time, there seems to have been more or less specu- 

 lative consideration of the subject with little attempt to approach the 

 problem by actual experiments. The present study details a series of 

 experiments which a^ ere devised in the hope of throwing light on the 

 subject. 



TECHNIQUE EMPLOYED. 



In view of the fact that Cooledge (.3) lias shoAvu that milk containing 

 agglutinins for Bact. abortus may contain the bacterium, the agglutina- 

 tion test was used in studying the milk fed to the animals. The in- 

 fectiousness of the milk was further controlled by guinea pig inocula- 

 tions. 



The term "naturally infected milk" which will be used in this paper, 

 implies a milk reacting positively to the agglutination test using Bact. 

 abortus as antigen and "non-infected milk" implies a non-reacting milk. 



The calves used in the experiment (excepting those fed non-infectious 

 milk) were separated from their respective dams shortly after birth in 

 order to safeguard against a possible infection from infectious material 

 which might have collected on the surface of the udder or teat. The 

 calves were fed about one gallon of milk from a pail twice daily. Every 

 precaution was taken to guard against an infection other than from the 

 milk. 



The results of the feeding of the milk were studied by means of the 

 agglutination and complement fixation tests upon the blood sera of the 

 calves, using Bact. abortus as antigen. The calves were bled from the 

 jugular vein periodically^ at intervals of about one week and the blood 

 sera tested. 



