CATTLE 369 



against 1 : 6 for milk production. That is to say, that the 

 fattening animal should have a balanced ration consisting 

 of one part protein food for every seven parts of carbo- 

 hydrates and fats. 



9. Diseases of Cattle 



Tuberculosis is a common disease among, cattle. It is 

 more common among dairy cattle than beef cattle. This is 

 probably because dairy cows are kept to a greater age than 

 beef cattle, and are more closely confined in barns. The 

 effects of tuberculosis in a dairy herd are (1) lowered milk 

 production and final loss of the tuberculous animal by death, 

 and (2) danger of giving the disease to people, especially 

 children who use the milk. 



Prevalence of tuberculosis in herds. There is no 

 way of telling the exact number of cattle affected by tuber- 

 culosis, as comparatively few herds are examined for the 

 disease. It is not uncommon to find as high as seventy to 

 eighty per cent, of the cows in a herd diseased, some with 

 the disease just starting, others with it well along, and still 

 others in the last stages. Since tuberculosis is contagious, 

 it is evident that when it once gets started in a herd it is 

 hard to stamp out. 



The tuberculin test. It is impossible to make certain 

 of the presence or absence of tuberculosis in a herd by any 

 set of symptoms. The only sure way is by the tuberculin 

 test. This test is required by law of all dairy herds in many 

 of the states. Experts have shown that tuberculin, if 

 properly used, will reveal the presence of tuberculosis in at 

 least ninety-eight per cent, of the cases. 



Tuberculin is a fluid in which tubercle germs have been 

 grown, but from which they have all been removed. This 

 fluid is injected with a hypodermic needle under the skin 



