10 



Experiment II. Feeding Feces from Positive-Reacting Birds to Pullorum- 

 Disease-Free Birds. 



Five groups of birds were used in this experiment. Group I consisted of eight 

 positive- and eight negative-reacting birds; Groups II and III each of 10 positive- 

 and 10 negative-reacting birds; Group IV of two positive- and five negative- 

 reacting birds; and Group V of 13 pos-tive- and 14 negative-reacting birds. 



Collection of Feces 



The positive-reacting hens were placed in coops with removable screen bottoms 

 and metal dropping trays. Newspapers were spread in the trays to facilitate 

 cleaning. Feces from the positive-reacting hens were collected each morning in 

 individual enamel cups. No feces were collected when eggs had been laid and 

 broken, allowing egg contents to mix with feces. After collection of feces, the 

 soiled newspapers were replaced each morning with clean newspapers. 



Feeding of Feces 



The positive and negative birds were paired so that each non-reacting female 

 received feces from the same positive hen throughout the experiment. The 

 collected feces were moistened sufficiently with tap water to mould into pellets 

 for feeding. Feedings were administered orally six mornings a week for eight weeks. 

 The non-reacting birds in Groups I and II were held for 24 weeks following the 

 last feeding of feces, and those in Groups III, IV and V for 8 weeks following the 

 last feeding of feces, at the end of which time the birds were killed and necropsied. 

 Groups I, II, III and IV received 25 grams of moistened feces at each feeding and 

 Group V received 15 grams at each feeding. 



Data in Table 6 show the numbers of positive-reacting hens and their ma.ximum 

 agglutination titres at the beginning of the experiment, the numbers of the non- 

 reacting birds, the number of feedings each bird received, and their maximum 

 agglutination titres exhibited during the experiment. 



All hens were tested at bi-weekly intervals by the tube agglutination test, 

 except Group V which was tested at weekly intervals. 



Results 



Group I. Seven of the eight non-reacting birds remained negative to the 

 tube agglutination test throughout the experiment, and S. pullorum was not 

 isolated on necropsy. The eighth hen (39348) developed agglutinins during the 

 fifth week and later a maximum agglutination titre of 1:5120 was attained. The 

 bird died on the 49th day after the last feeding. S. pullorum was isolated from the 

 pericardial fluid, liver, spleen and ovary. 



Croup II. All of the non-reacting hens remained negative to the tube agglu- 

 tination test throughout the experiment, and 5. pullorum was not isolated on 

 necropsy. 



Group III. Eight of the ten non-reacting birds remained negative throughout 

 the experiment, and S. pullortim was not isolated on necropsy. The remaining 

 two birds (60971 and 60975) developed agglutinins during the second and fourth 

 weeks, respectively. The maximum agglutination titres exhibited by hens 60971 

 and 60975 were 1:2560 and 1:5120, respectively. S. pullorum was isolated from 

 the ovary and spleen of 60971 and from the ovary of 60975. 



