DAIRYING 59 



needed for testing the cows. The tuberculin should not be used 

 if it has become turbid, and it should be kept in a cool place, pro- 

 tected from light. 



DIRECTIONS FOR TUBERCULIN TESTING COWS. 



758. The syringe and needle should be placed in boiling 

 water for at least 5 minutes just before using them. 



The temperature of each animal to be tested should be taken 

 several times (about once in 2 hours) during the 12 hours preced- 

 ing the injection of the tuberculin. The temperatures are all 

 taken by inserting the thermometer into the rectum of the animal, 

 where it should remain for 3 to 5 minutes before removing. The 

 temperature is at once read and recorded. If these preliminary 

 temperatures run as high as 103 F., the tuberculin test of such 

 animals cannot be depended on, and cattle in advanced stages of 

 tuberculosis do not respond to the test. The general appearance 

 of such cattle, however, is usually sufficient evidence of their 

 diseased condition. 



Very few animals are included in these two exceptions, and 

 the preliminary records of temperature nearly always show a 

 normal condition. 



759. After these records have been made through the day, 

 the tuberculin is injected between 8 and 10 p. m. of the same day. 

 About 1.5 cc. tuberculin is a dose for stock under two years old; 

 2 cc. for mature cows, and 3 cc. for bulls and large cows. 



760. The tuberculin is injected by means of the needle and 

 syringe under the skin, either at the side of the neck or just be- 

 hind the shoulder blade. The next morning, temperature records 

 should be made again about once in 2 hours from 6 a. m. until 

 evening. If these show a rise of 2 degrees or more above the 

 temperature of each cow, as recorded before the injection of the 

 tuberculin, this rise in temperature is an indication that the animal 

 has tuberculosis, or it "reacts." Animals that do not show a rise 

 in temperature to 103 F. during the day after the injection of 

 tuberculin are not tuberculous. 



