DISTRIBUTION OF TESTS AND REACTORS 



Table 1 gives the number of tests and reactors by counties. A total of 1,272,547 

 chicken samples was tested, of which 0.10 percent were positive. Flocks were 

 tested in 12 counties. Middlesex and Plymouth Counties led in the number of 

 samples tested. Over 86 percent of all the samples tested were received from 

 six counties (Bristol, Essex, Middlesex, Norfolk, Plymouth, and Worcester). 

 Three counties (Barnstable, Dukes, and Hampshire) revealed no reactors, whereas 

 only one county exceeded 0.5 percent positive tests. >.« ^ 



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

 Australorp, Brahma, Columbians, Crosses, Eisenbars, New Hampshire, Rhode 

 Island Red, Salmon Faverolles, White American, White Leghorn, White Ply- 

 mouth Rock, Wyandottes (Golden, Silver Laced, Spangled, White). 



The predominating breeds were Rhode Island Red; Barred Plymouth Rock, 

 and New Hampshire. Of the total samples 46.25 percent were taken from Rhode 

 Island Red, 24.64 percent from Barred Plymouth Rock, 24.05 percent from New 

 Hampshire, and the balance from the other breeds listed. 



Of the 1,155,031 samples collected from females, 52,299 were from hens and 

 1,102,732 from pullets, with 0.03 and 0.11 percent reactors, respectively. The 

 117,516 samples collected from males gave 0.08 percent positive tests. 



ANNUAL TESTING OF FLOCKS 



The results from flocks tested for the first time, intermittently, for two con- 

 secutive years, and for three or more consecutive years are given in Table 2. 



The 49 flocks tested for the first time represented 58,442 tests, of which 0.16 

 percent were positive. In this group 45 flocks, containing 93.34 percent of the 

 birds, were found to be non-reacting and four flocks were positive. The average 

 number of birds per flock was 1,143. 



The group tested intermittently was the smallest of the four, both in number 

 of flocks and in number of birds tested. The average percentage of positive tests 

 was 0.14. Only two flocks were positive and 18, representing 89.3 percent of the 

 birds, were non-reacting. The average number of birds per flock was 2,102. 



In the group tested for two consecutive years, 60 flocks were non-reacting and 

 five were positive. The average percentage was the highest for the four groups, 

 which is attributed to the fact that a few flocks had a high percentage of reactors. 

 In this group 87.2 percent of the birds tested were in non-reacting flocks. The 

 average number of birds per flock was 1,931. 



Table 2. Annual Testing Versus Single and Intermittent Testing 



