10 MASS. EXPERIMENT STATION BULLETIN 311 



Table 6. Results of the Vaccination of Flocks in the Field. 



Number Age Number of Takes Total 



Group of in Percentage 



Birds Weeks First Vaccination Second Vaccination of Takes 



+ + 



Flock 1 



Total 1,402 1.294 108 46 62 95.58 



Flock 2 



1 4S1 10 442 39 6 33 93.13 



2 431 20 347 84 14 70 83.73 



Total 912 789 123 20 103 8S.71 



Flock 3 



98 . 66 

 99.33 

 100 . 00 



Total 450 447 3 99.33 



Flock 4 



Total 4,040 3,974 66 ::i 



Total 3, I 3.427 173 



Flock ' 

 1 BOO 20 768 32 



•Of these birds 30 died as the disease had appeared two days before vaccination in two pens. 

 ♦♦Take.-, for the second vaccinal : ."ii were estimated, since onl) pari of the birds were examined. 



