24 MASS. EXPERIMENT STATION BULLETIN 407 



54. Is it necessary to test all birds on the premises? To determine the exact 

 disease status of the entire flock, it is necessary to test all the birds on the premises. 



55. Is it safe to retain a few untested culls on the premises for a short time 

 after the test? Untested culls should always be regarded as dangerous to the 

 tested flock even under the best of quarantine conditions. The safest procedure 

 is either to cull and dispose of the undesirable birds before the test or to test all 

 the birds on the premises. 



56. Is it safe to retain untested birds in separate houses for egg and meat 

 production? No. The practice of keeping untested birds on the premises for 

 egg and meat production is one of the causes for failure to establish or maintain 

 a pullorum disease-free flock. Most poultry plants are so organized and managed 

 that no quarantine measures could be successfully executed on the two types of 

 flocks. 



57. Why should the entire flock be tested at one visit? Testing of the entire 

 flock at one visit permits the flock owner and the blood collector to check more 

 accurately whether all the birds have been tested. It prevents untested birds 

 from mixing with the tested birds. It assures more economical and satisfactory 

 routing of the blood collector. In a large testing program it may not always be 

 possible to test the entire flock at one visit; but so-called "split-flock" testing 

 should be kept at a minimum in order to facilitate the establishment and main- 

 tenance of pullorum-free flocks. 



58. How should tested birds be marked? All tested birds should be banded 

 with an official sealed band in order that their future identification may be accu- 

 rately associated with their testing history. 



59. Is retesting advisable in infected flocks? In retesting infected flocks one 

 should take into account the value of the stock, the amount of infection, and the 

 arrangement and mode of operation of the plant. The value of the stock is 

 probably the primary consideration. If the value does not warrant the expendi- 

 ture for retesting, then the inferior infected flock should be sold and replaced with 

 pullorum disease-free stock. When the flock is heavily infected, retesting is 

 usually not advisable because the size of the flock will be so reduced that a profit- 

 able breeding program can not be followed. Furthermore, the eradication of 

 infection often appears to be more difficult In such cases than where the amount 

 of infection Is small. Sometimes the arrangement and operation of the plant are 

 such that a retesting program can not be applied effectively. If the nature of the 

 flock and condition of the plant do not warrant or permit efTective retesting, 

 then the flock should be replaced with pullorum disease-free stock. 



60. How many tests are necessary to eradicate the disease from a flock? 



The number of tests required to eradicate the disease Is Influenced by the con- 

 dition of the birds, the amount of Infection, the condition and management of 

 the plant, and the quality of the test. With one exception, five retests conducted 

 at approximately four-week intervals within one season have been the maximum 

 number necessary to eliminate the infection from a flock in Massachusetts. 

 In the one Instance 17 retests failed to eliminate the Infection completely. In 

 some flocks only two retests were necessary. 



61. Should infected or reacting birds be culled as soon as detected? Yes. 



Infected or reacting birds should always be regarded as spreaders of the disease. 

 Therefore, immediate culling and disposal of such birds is recommended 



