6 



It was also noted that, in a rather high percentage of the flocks tested 

 for the first time, only part of the birds was tested. 



There were 14 flocks in the intermittent testing group, in 9 of which 

 only part of the birds was tested. Intermittent and partial flock testing is 

 conducive to permitting infection to become established in a Mock. 



Flocks tested for two consecutive years show that flock owners in this 

 group, on the whole, have a better knowledge of disease eradication and 

 prevention than owners who test for the first time or intermittently. 



In the group tested for three or more consecutive years, which is the 

 largest of the four groups, the outstanding feature is the fact that it is 

 the highest of all the groups in percentage of infection. However, 3,079 

 reactors were found in two large flocks, leaving only 83 reactors (.02 

 percent) detected among 389,755 birds in 210 flocks. Three of the in- 

 fected flocks in this group have had infection for two or more consecu- 

 tive years. 



It is very encouraging to note that 188 flock owners in this group had 

 all their birds tested and no reactors were found. However, there is still 

 considerable opportunity for improvement, since 66 of all the flocks tested 

 were either infected or only partially tested, or both. As long as flocks 

 remain in the c e classifications, they cannot be considered eligible for 

 official recognition by the Massachusetts Department of Agriculture. In 

 all, 280 flocks representing 460,045 birds were 100 percent tested and non- 

 reacting. Among these flocks the majority have been tested and found 

 negative for three or more consecutive years. Such flocks are safest 

 for breeding from the standpoint of pullorum-disease control and erad- 

 ication. 



Appearance of Infection in Flocks Previously Negative 



During the past year, infection was detected in six flocks which had 

 been negative for one or more years. In all but one flock, the amount of 

 infection did not exceed 1 percent, as is shown in Table 3. The source 

 of infection could not be definitely accounted for in all instances. From 

 the information at hand, it appears that the owners of these flocks may 

 not fully appreciate the possible avenues through which pullorum disease 

 may be introduced. 



Poultrymen in general could greatly strengthen their preventive meas- 

 ures by prohibiting the traffic of used equipment, whatever it may be. 

 onto the premises. Furthermore, poultry dealers, agents, feed dealers, and 

 visitors should not be permitted to enter the poultry houses and ranges. 

 Of the possible vectors that may play a role in disseminating pullorum 

 disease, the infected bird, infective egg, contaminated soil, equipment, feed, 

 and litter appear the most likely sources for infection. If poultrymen can 

 set up effective barriers against such potentially dangerous vectors, few 

 if any breaks will occur. Free flying birds may be a possible vector, but 

 this appears rather remote. 



Reinfection of a flock is costly to the owner. It usually disturbs his 

 trade and may involve considerable expense in eliminating the infection. 

 Therefore, every poultry breeder should exercise all precautions possible 

 to prevent the introduction of infection. It must be remembered that 

 testing does not prevent birds Erom becoming infected. Its sole purpose 

 is to detect infected birds so that they can be eliminated from the flock. 

 A negative flock lias no assurance of remaining free of the disease if the 

 owner does not exercise proper precautionary measure. 



