686 EXPERIMENT STATION RECORD. 



The elimination of tubercle bacilli from infected cattle, and the control 

 of bovine tuberculosis and infected milk, V. A. Moore ( Hiew York Cornell 8ta. 

 Bill. 299, pp. 691-1 l.'i). — This bulletin first describes the channels through which 

 tubercle bacilli get into the milk of infected cows and the frequency with which 

 market milk is found to contain them. 



Numerous examinations were made in order to gain definite knowledge of the 

 frequency with which this bacillus occurs in the milk and feces of cows that 

 react to tuberculin. In preliminary work a total of 136 samples of milk and 

 36 of feces were examined. Of the milk samples, 49 were mixed and 87 were 

 from individual cows, 2 with diseased udders. In all, 80 guinea pigs were 

 inoculated, each receiving 2 cc. of the sediment from the centrifuged tube. 

 Sixteen of the pigs were injected in the abdominal cavity, while the others re- 

 ceived the sediment subcutaneously. The results of these examinations were as 

 follows : 



" Of the 49 examinations of mixed milk, tubercle bacilli were found in one 

 specimen microscopically and no inoculations were made. Later experience 

 suggests that possibly these were acid-fast organisms other than true tubercle 

 bacilli. It was not known to us whether or not clinical cases existed in this 

 herd. Guinea pigs inoculated with the mixed milk from 2 herds developed 

 tuberculosis. In these herds it was known that there were clinical cases. 

 After these were removed subsequent inoculations gave negative results. The 

 guinea pigs inoculated with the samples from the other mixed milk either died 

 within a few days from sepsis, or remained well. Thus there were 2 of the 49 

 samples that contained infecting organisms and possibly the third did also. 

 This gives as the maximum a little over 6 per cent that contained tubercle 

 bacteria. 



" Of the 87 examinations of the milk from individual cows, tubercle bacteria 

 were not found either microscopically or by guinea pig inoculations except in 

 2 cases, and these were samples of milk from the cows whose udders were 

 affected. They were the only cows that showed any clinical evidence of disease, 

 and at the time the lesions in the udders were not thought to be of a tubercu- 

 lous nature. Tubercle bacilli were present in very large numbers in the milk 

 from each of these cows. The bacilli were largely outside of the tissue cells, 

 lying free between the leucocytes and fat globules of the milk. In 2 speci- 

 mens acid-fast or timothy bacilli were present in very small numbers. They 

 were decolorized with acidulated alcohol. Guinea pigs inoculated from these 

 samples did not develop tuberculosis. If we exclude the 2 cases in which 

 there was udder affection, tubercle bacteria were not found in any of the sam- 

 ples. If they are included, a little over 2 per cent of the examinations were 

 positive. 



" The 36 examinations of the feces failed to reveal the presence of tubercle 

 bacteria, either microscopically or by animal inoculation. One specimen con- 

 tained a few acid-fast organisms. The guinea pig inoculated from this specimen 

 did not develop tuberculosis." 



The results obtained from repeated examinations of milk and excreta of re- 

 acting cows, and from feeding the milk of such cows to young pigs during the 

 time the milk and feces were being examined microscopically and guinea pigs 

 were being inoculated, lead the author to conclude that " the spread of tubercle 

 bacilli is not generally taking place, at least to any detectable degree, from 

 occult cases of bovine tuberculosis. The evidence thus far gathered is quite 

 as conclusive that cows with udder tuberculosis are eliminating tubercle bacilli 

 in large numbers with their milk, and that advanced cases of pulmonary tuber- 

 culosis, or perhaps earlier ones in which the lesions are discharging into the 



