18 MASS. EXPERIMENT STATION BULLETIN No. 284 



53. — Can birds be tested on range? Birds may be succes.sfully tested on 

 range provided suitable facilities are available. Range testing is recommended 

 for infected flocks so that the bulk of the infection will not be moved into the 

 laying quarters where the birds are more congested and there is greater oppor- 

 tunity for spread of the disease. 



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? llntested culls should always be regarded as dan- 

 gerous 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 puUorum 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 tested birds. It assures more economical and satisfactory 

 routing of the blood collector. 



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

 banded with an official sealed band in order that their future identification can 

 be accurately associated with their testing history. 



59. — Is re testing advisable in infected flocks? In retesting infected 

 flocks one should consider the value of the stock, the amount of infection, and 

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

 is probably the primary consideration. If the value does not warrant the expen- 

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

 with pullorum disease-free stock. In the majority of cases when the flock is 

 heavily infected, retesting is not advisable because the size of the flock will be 

 reduced to such an extent that a profitable breeding program cannot 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 ar- 

 rangement and operation of the plant are such that a retesting program cannot 

 be applied effectively. If the nature of the flock and condition of the plant do 

 not warrant or permit effective 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 condition of the birds, the amount of infection, the conditions and the manage- 

 ment of the plant and the quality of the test. In Massachusetts five retests within 

 one season have been the maximum number necessary to eliminate* the infection 

 from a flock. In some flocks only two retests were necessary. 



