46 



CONTROL SERIES No. 63 



Table i8 — Serological and Necropsy Data Concerning Fourteen Artificially 

 Exposed Chicks (Part V) 



Agglutination Reaction 



Chick Sex Age when 5. 



No. Detected Maximum Age At Necropsy pullorum 



as Reactor Titer Isolated 



Remarks Titer Age 



Weeks Weeks Weeks 



253* M .... Died 80** S + 



254 F 6 1,280 6 Died 320 8 — 



259* F .... Died 8 — 



260* M .... Died 8 — 



261* F .... Died S — 



270 F 5 160 5 Died 20** 8 — 



271* M .... Died 40** 8 — 



268 F 4 1,280 7 Died 160 11 + 



251* M .... Killed 14 — 



269* M .... Killed 14 — 



257 M 9 80 9 & 10 Killed 40** 15 — 



265 M 7 320 8 ,13 & 14 Killed 320 15 — 



266 M 8 320 11 & 12 Killed 160 15 + 

 273 M 7 640 7 Killed 40** IS — 



* Not considered a reactor at any time. 

 ** Agglutination not complete in 1:20 and higher dilutions. 



isolated. The second was killed because of infectious laryngotracheitis at approx- 

 imately 9 months. Extensive lesions suggestive of pullorum disease were ob- 

 served, and 5. pullorum was isolated. The agglutination titer of this bird had 

 been considered as suspicious on several tests. At necropsy, its serum completely 

 agglutinated S. pullorum antigen in the 1 :20 dilution. S. pullorum was not iso- 

 lated from the other 4 non-reacting pullets. 



The 4 reacting pullets in Group A-1 were killed 2 months after having at- 

 tained sexual maturity, and data are presented in Table 19. 5. pullorum was 

 isolated from 2 birds. The agglutination titers of the other 2 gradually became 

 lower, and they were not regarded as reactors at the time of necropsy. 



Table 19 — Serological and Necropsy Data Concerning Four Pullets 

 Exposed to Artificial Infection as Chicks (Part V) 



The 54 control chicks were tested at biweekly intervals after the age of 5 

 weeks. At the age of 3 months, all but 10 pullets were used for other purposes. 

 These 10 birds were retained until approximately 8 months of age, when all but 

 2 had attained sexual maturity. No reactors were detected among these con- 

 trols at any time. 



Discussion 



5. pullorum infection was suspected to be present in the 15 chicks, 5 to 19 

 days of age, of the miscellaneous consignments on account of the histories and 



