Table 7. Nineteen-Year Pullorum Disease Testing Summary 



♦Based on total birds tested: 1927-28, 190.658 birds; 1928-29, 254,512 birds. 



Comments and Suggestions 



A critical study of the testing results for the past year suggests the following 

 items that should receive the attention of the Massachusetts poultry industry. 



1. Annual testing — Among the 308 flocks tested during the 1937-38 season, 

 65 were not tested this past season. The majority of these flock owners dis- 

 continue the testing for one or two years and sometimes longer. Such a practice 

 is designated as intermittent testing. The testing results of several years show 

 that intermittent-tested flocks are apt to show a higher flock incidence of infection 

 than flocks tested annually. In consideration of the fact that flocks once free 

 of the disease do occasionally become re-infected through obscure channels or 

 through gross mismanagement practices, annual testing is strongly advocated to 

 prevent the infection from becoming well established in such a flock. Further- 

 more, the purchasers of pullorum-free stock cannot buy with the same assurance 

 from a flock not tested for two or three years as they can from a flock tested within 

 a year of the date of sale, even though both flocks were negative on the last test. 

 The true status of a flock can be determined only through testing, and the re- 

 liance on the value of a test should become increasingly less the greater the interval 

 becomes between the date of the test and date of sale of stock from the flock. 



2. Testing all birds on the premises — Each year some poultrymen test only 

 part of the birds on the premises. In a few instances such a practice has ap- 

 parently been successful in determining the true status of the flock. However, 

 there is no definite assurance, when a negative test is obtained with a partial 

 flock test, that the untested portion of the flock is also negative. Regardless 

 of the purpose for which untested birds may be retained, there is always the 

 possibility of the spread of infection from untested to tested birds by means of 

 the caretaker, equipment, feed, litter, and even cohabitation of tested and un- 

 it 



