328 DAIRY CATTLE AND MILK PRODUCTION 



herd tested once per year to make certain the disease has 

 not gained access. 



The question is often raised as to the accuracy of the 

 tuberculin test. It has been thoroughly demonstrated that 

 this method seldom if ever fails in the hands of a person 

 who understands its use. Authorities on the subject state 

 that 97 per cent of animals reacting to the test have shown 

 lesions on diagnosis. The test is made by first taking the 

 temperature of each animal three or four times at intervals 

 of two hours. Tuberculin is then injected beneath the skin 

 with a hypodermic needle. After about 9 hours the tem- 

 perature reading is again taken, and repeated every two hours 

 until three or more readings have been made. A dairyman 

 accustomed to the use of such instruments can conduct the 

 test himself, if he wishes, after having first assisted some 

 competent operator to carry out the test. However, it is 

 always safer to have the work done by a trained veterinarian, 

 in order that no mistakes may be made and that the test 

 will be recognized by health officials and by prospective 

 buyers. When the testing is done by the owner himself, he 

 should consult with the State Veterinarian or Live Stock 

 Board that has the matter in hand for his state. 



Abortion. This term is used by cattlemen to indicate 

 the expulsion of the fetus at any time before completion of 

 pregnancy. Abortion may be contagious or non-contagious. 

 The non-contagious cases may occur as the result of injury, 

 as a fall, or from the kick of a horse, or by being crowded in 

 a doorway. Poor feed, especially that deficient in protein 

 or mineral matter, sudden change of feed, severe cases of 

 indigestion, such as bloating, may also be the cause. It is 

 also claimed that offensive odors may bring about the same 



