Among the other groups increases in the number of flocks and tested birds 

 over the previous season have also been noted. The percentages of positive 

 tests for the groups tested for the first time and tested intermittently are 

 greater than those in the remaining groups. This is as one might expect, 

 although the percentage of positive tests in the group tested for the first time 

 is far less than that of the previous season. This fact is encouraging, since it 

 gives the flock owners in this group a greater incentive to continue testing and 

 employing measures to establish and maintain a clean flock. 



A total of 281 non-reacting flocks were detected, of which 48 were tested 

 partially. Among 281 non-reacting flocks, 157 (55.8 percent) were in the 

 group tested for three or more consecutive years. 



Twenty-six positive flocks are listed in Table 2. The group tested for the 

 first time leads in the number of positive flocks. 



Fifty-nine flocks, representing 19.2 percent of the total flocks, were partially 

 tested. However, it is encouraging to note that the percentage of flock owners 

 who tested all the birds on the premises has increased from 79.3 in 1935-36 

 to 80.7 in 1936-37. Partial flock testing, although apparently successful in 

 some cases, as a general rule fails to determine the true status of the flock and 

 sooner or later brings grief to the owner. The testing of all birds on the premises 

 enables one to determine the true status of the entire flock and eliminates the 

 necessity for quarantine measures that should be practiced in a partially 

 tested flock. A flock once free from the disease does not necessarily continue 

 without pullorum infection. 



In discussing the data in Table 2, one may conclude that pullorum-disease 

 eradication has made the greatest progress in flocks that are subjected to 

 annual testing and sound eradication and preventive measures. It is hoped 

 that further progress can be made by reducing or eliminating the number of 

 partially tested flocks. 



Appearance of Infection in Flocks Previously Negative 



In a disease eradication program the subject of infection re-appearing in 

 previously non-reacting flocks is one of great concern to the poultry industry. 

 According to present knowledge regarding the transmission of the disease, 

 pullorum infection may be disseminated through numerous channels. Know- 

 ing that scattered foci of infection still exist within the State as well as out of 

 State, dissemination of the disease to previously non-reacting flocks may be 

 expected if proper preventive measures are not exercised. ■ 



In Table 3 are listed six flocks that were non-reacting in 1935-36 but revealed 

 infection in 1936-37. It is of interest to note that in all ca.ses but one the 

 reactors did not exceed 0.50 percent. The source of infection could not be 

 satisfactorily explained in four flocks. Flock 3 revealed infection the previous 

 season and was retested by the pen method. It is quite possible that this 

 method of testing failed to detect all of the infection which manifested itself 

 in the progeny the following season. The safest retesting procedure for in- 

 fected flocks is to retest all birds in the flock, which permits one to determine 

 the true status of each individual bird. The owner of Flock 4 returned a pen 

 of birds from an egg-laying contest and when these were tested one infected 

 bird was detected. This incident points out, as have previous cases of a 

 similar nature, that birds returned from egg-laying contests or shows may be 

 infected with diseases foreign to the flock from which they originated. There- 

 fore, one should not jeopardize the health standing of a flock by carelessly or 



(5) 



