For the four groups as a whole 458 flocks were tested, representing 1,179,481 

 birds and 1,213,073 samples, of which 0.04 percent were positive. The 439 flocks 

 which were 100 percent tested and non-reacting contained 1,161,599 birds or 99.1 

 percent of the total birds tested. Six flocks were classified as positive, represent- 

 ing 8,118 birds. The average percentage of reactors among these birds was 0.71. 

 These results show that the amount of pullorum infection has been reduced to a 

 very low level. 



During the past year 108 or 21.86 percent of the flocks tested in 1947-48 

 were not tested this season. This is a smaller number of flocks than dropped out 

 the previous season. However, progress in pullorum disease eradication is 

 greatly influenced by annual testing of flocks. Intermittent testing may permit in- 

 fection to become well established, consequently making it more difTicult and 

 costly to re-establish a pullorum-clean flock. Flock owners are urged to test 

 their flocks annually in order to determine the true pullorum status of the birds. 

 By adopting such a program along with other effective eradication measures, 

 flock owners are likely to succeed in developing pullorum-clean flocks. 



APPEARANCE OF INFECTION IN FLOCKS PREVIOUSLY NEGATIVE 



During the past year reactors were found in si.x flocks which had been non- 

 reacting the previous year. The testing results of these flocks are given in Table 3. 

 Three flocks had been negative for one 3'ear, two flocks for five years, and one 

 flock for eight 3'ears. Five flocks had less than 1 percent infection. In flocks 3, 4, 

 and 6 entire infected pens of birds were sold immediately after infection was de- 

 tected. All six flocks were retested and no additional infection was detected in 

 the mature birds. 



Table 3. Appearance of Infection in Flocks Previously Negative 



^Represents retests 



