DISTRIBUTION OF TESTS AND REACTORS 



A total of 1,144,832 chicken samples from 11 counties was tested, and the pei- 

 centage of positive tests was 0.01 . No reactors were detected in eight counties. Also, 

 the Barred Plymouth Rocks and White Leghorns tested revealed no reactors. Ply- 

 mouth, Bristol, Essex, and Middlesex Counties led in the number of samples tested. 



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

 Columbian, Cornish, Crosses, Delaware, New Hampshire, Rhode Island Red, White 

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



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

 Hampshire, and White Leghorn were the predominating breeds tested. Of the total 

 samples tested, 35.19 percent were taken from White Plymouth Rock, 18.86 percent 

 from Rhode Island Red, 17.60 percent from Barred Plymouth Rock, 12.33 percent 

 from the New Hampshire, and the remainder from other breeds. 



Of the 1,043,942 samples collected from females, 26,867 were from hens and 

 1,017,075 from pullets, with 0.004 and 0.013 percent reactors, respectively. Among 

 the 100,890 samples collected from males, 0.004 percent were positive. 



ANNUAL TESTING OF FLOCKS 



Table 2 lists the result from flocks tested (1) for the first time, (2) intermittently, 

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



In the group tested for the first time, 61 reactors were detected in one flock 

 that was subjected to an intensive retesting program, which was successful in elim- 

 inating the infection from the flock. More flocks and birds were tested in this group 

 than during the previous season. The average percentage of reactors (0.08) was 

 also considerably less. The average number of birds to a flock in this group was 

 2,405. 



In the intermittent group no reactors were detected. The average number of 

 birds to a flock was 2,865. In this group fewer flocks and birds were tested than in 

 the other groups. 



In the two-year group the 23 reactors were identified in one flock. The infec- 

 tion in this flock was eliminated through retesting. The average number of birds 

 to a flock was 2,736. 



Table 2. Annual Testing Versus Single and Intermittent Testing 



