-6- 



In the group tested for three or more consecutive years there were 323 flocks, 

 representing 1,181,854 tests, of which 0.019 were positive. A total of 318 non- 

 reacting flocks was detected, which inchided 98.29 per cent of the birds tested 

 in this group. Five flocks were classified as positive. The average number of 

 birds per flock was 3,579. 



For the four groups as a whole, 417 flocks were tested, representing 1,343,955 

 birds and 1,370,430 samples, of which 0.016 per cent were positive. The 395 

 flocks that were 100 percent tested and nonreacting contained 1,295,129 birds 

 or 96.37 per cent of the total birds tested, 



During the past year, 88 or 19.64 per cent of the flocks tested in 1950-51, were 

 not tested. Records reveal that only a small percentage of the flock owners resort 

 to an intermittent testing program. The majority of flock owners who discon- 

 tinue testing do so permanently. However, this does not alter the fact that 

 annual testing is essential in the control and eradication of the disease. An 

 effective program for maintaining pullorum-clean flocks includes annual testing. 



APPEARANCE OF INFECTION IN FLOCKS PREVIOUSLY NEGATIVE 



During the past year, pullorum "breaks" were observed in eight flocks, two 

 more than in the previous season. The "breaks" this past year were considered 

 more serious in that a number of flock owners were forced to discontinue their 

 hatching egg production. In five instances the source of infection was unknown; 

 and in the remaining three flocks, introduction of infected stock and returning 

 birds from shows were regarded as the reason for the "breaks." 



Table 3 gives information regard ng "breaks" observed during the past 13 

 years. The percentage of "breaks" has increased slightly over the previous season. 

 Although the number may be considered small, it should be realized that "breaks" 

 on the whole constitute a serious loss to the flock owner. Furthermore, each 

 "break" may serve as an additional focus of infection for disseminating the dis- 

 ease to other flocks. Flock owners are urged, therefore, to maintain strictest 

 vigilance against the introduction of the disease. 



The foUowing measures have been found to be effective in establishing and 

 maintaining a pullorum-free flock: 



1. All the birds on the premises should be tested each year. 



2. If infection is present, the entire flock should be retested within four to 

 six weeks until a negative report is obtained, provided the value of the birds 

 justifies the expenditure. 



3. Every reactor, regardless of its value, should be removed from the 

 premises and sold for slaughter immediately upon receipt of the reports. 



4. Offal from aU birds dressed for market or home consumption as well as 

 dead birds that are not fit for consumption should be burned. 



5. The poultry houses, runs, and equipment should be thoroughly cleaned 

 and disinfected immediately after removal of reactors. An empty pen to each 

 house should be provided to facilitate cleaning and disinfection during the winter 

 months. Disinfectants approved by the United States Department of Agri- 

 culture should be used. 



