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By ROLAND W. WINTERFIELD and 

 EDWARD H. SEADALE 

 Department of Veterinary Science 



VACCINATE THEMSELVES 



THE "Do It Yourself" trend so 

 popular today has apparently tak- 

 en hold in the chicken yard. Chick- 

 ens are doing a successful job of 

 vaccinating themselves against New- 

 castle disease, a respiratory and 

 nervous infection of poultry. 



old method tedious 



Before the poultry industry in- 

 creased in size and became more and 

 more mechanized, the old method of 

 vaccinating birds individually by 

 administering vaccine through the 

 eye was adequate, but today this 

 process is tedious and time-consum- 

 ing. 



Searching for a more efficient 

 procedure, research men explored 

 the possibility of mass application 



of vaccines. Experiments under 

 controlled conditions have proved 

 that mass vaccination of birds 

 through drinking water, dust, or 

 spray with mild strains of Newcastle 

 disease virus is as satisfactory a 

 method as the vaccination of indi- 

 vidual birds. 



Thus far. commercial poultrymen 

 have been enthusiastic about this 

 mass method. 



dosage important 



A vaccine may contain enough virus 

 particles to immunize chickens when 

 it is administered through the eye. 

 However, when the same vaccine is 

 diluted in drinking water, immunity 

 may not be satisfactory, unless the 

 vaccine is very potent. 



A white, powdery protein-stabil- 

 I izer is mixed with the vaccine be- 

 fore adding to the drinking water. 



