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 number of flocks tested for the first time exceeds the number tested inter- 

 mittently and for two consecutive years, and the average percentage of reactors 

 was higher than for any other group. However, it is particularly encouraging 

 that all but five flocks were found to be negative. Also, 95 percent of the birds 

 tested in this group were in flocks identified as negative. The average number of 

 birds per flock in this group was 1,209. 



In the intermittent group are listed seven infected flocks. Of the birds tested 

 in this group, 91 percent are in non-reacting flocks, which is a lower percentage 

 than in the other groups. These results substantiate previous reports that inter- 

 mittent testing is not a sound procedure in establishing or maintaining a non- 

 reacting flock. The average number of birds per flock in this group was 3,059. 



In the flocks tested for two consecutive years, 97 percent of the birds tested 

 are in non-reacting flocks. This exceeds the percentage in the groups te.sted for 

 the first time and intermittently. The average number of birds per flock in this 

 group was 1,949. 



The group tested for three or more consecutive 3'ears is by far the largest of 

 the four groups. It also has the lowest average percentage of reactors as well as 

 the largest number of negative flocks and of birds in such flocks. Approximately 

 97.4 percent of the birds tested in this group are in non-reacting flocks, which is 

 indeed very encouraging. The average number of birds per flock in this group 

 was 2,339. 



For the four groups as a whole, 538 flocks were tested, representing 1,125,737 

 birds and 1,225,594 samples, of which 0.12 percent were positive. The 498 flocks 

 which were 100 percent tested and non-reacting contained 1,073,565 birds or 95.3 

 percent of the total birds tested. This is 2 percent higher than the previous 

 season in spite of the marked increase in the number of birds tested this season. 



