DISTRIBUTION OF TESTS AND REACTORS 



Table 1 reveals that 1,168,739 samples were received from chicken flocks in 

 12 counties. The percentage of reactors was 0.04. Middlesex, Plymouth, Essex, 

 and Worcester Counties lead in the number of samples tested. No reactors were 

 detected in Barnstable, Berkshire, Dukes, Hampden, Norfolk, and Worcester 

 Counties. In all except two of the remaining counties the percentage of reactors 

 did not exceed 0.003. 



The following breeds were tested: Bantam, Barred Plymouth Rock, Brahma, 

 Columbian, Cornish, Crosses, Delaware, Eisenbar, New Hampshire, Rhode Island 

 Red, White American, White Leghorn, White Plymouth Rock, White Wyandotte. 



The Rhode Island Red, New Hampshire, Barred Plymouth Rock, and White 

 Plymouth Rock were the predominating breeds tested. Of the total samples, 27.30 

 percent were taken from Rhode Island Red, 22.20 percent from New Hampshire, 

 21.79 percent from Barred Plymouth Rock, 19.81 percent from White Plymouth 

 Rock, and the balance from other breeds tested. Of the 1,064,198 samples collected 

 from females, 40,632 were from hens and 1,023, .566 from pullets, with 0.20 and 

 0.04 percent reactors, respectively. Among the 104,541 samples collected from 

 the males, 0.01 percent were positive. 



ANNUAL TESTING OF FLOCKS 



Table 2 lists the results from flocks tested (1) for the first time, (2) inter- 

 mittently, (3) for two consecutive years, and (4) for three or more consecutive years. 



The number of flocks, birds, and samples tested in the first three groups does 

 not vary markedly. The higher percentage of positive tests in the first group was 

 due to a heavy infection in one flock. Only two flocks in the first three groups 

 were classified as positive at the close of the season. These results suggest, as has 

 been mentioned before, that flocks tested intermittently usually reveal a higher 

 incidence of infection than flocks tested for two or more consecutive years. The 

 average number of birds per flock in the respective groups is as follows: first year, 

 1,337; intermittent, 2,023; and two consecutive years, 2,529. 



Table 2. Annual Testing Versus Single and Intermittent Testing 



