Complications which sometime follow infectious bronchitis inocula- 

 tions were in greater number in the fall and winter months. The average 

 length of time of respiratory symptoms in the year 1950 was 26 days as com- 

 pared to 18 days in 1951. While this may be affected by the total number of 

 birds, it is interesting to note. The mortality following vaccination in 1950 

 was 2.02 percent as compared to 2.20 percent in 1951. The mortality is 

 based on field observations without recourse to laboratory findings. This in- 

 dicates the vaccination program as a whole is reasonably satisfactory. But 

 it is the individual flocks which have the problems of infectious bronchitis 

 vaccination. 



In an effort to find out if some immediate control could be given to bring 

 relief from some of these cases, two drugs were tried — iodine and anti- 

 histamine. These were administered in the water at various times and levels, 

 both when the respiratory symptoms appeared and before they appeared. 



Finally, antihistamine was given in the vaccine when administered. In 

 no instance could any value be dervied from the drugs in controlling un- 

 toward reactions. W. R. Dunlop 



Is It Possible for Chicks Under Four Weeks to be Vaccinated 

 by the Wing Web Modified Live Virus Newcastle Vaccine? 



Contrary to earlier knowledge, this appears to be possible, in parentally 

 immune chicks. On experimental trial, groups of birds were made up from 

 range-reared stock which were vaccinated at 14 weeks of age by the wing 

 web method. At 24 weeks one group was revaccinated by the modified live 

 virus wing web method. 



Following inoculation, eggs were saved from both groups for a period 

 of 11 days. One half of the eggs from the revaccinated group were selected 

 for virus isolation. In no case was the virus of Newcastle disease recovered. 

 The remaining eggs of the revaccinated group and those of the group vacci- 

 nated once were incubated. It was demonstrated that the difference in total 

 infertile eggs was slight. However, the difference in dead germs and the per- 

 centage hatch appeared significant, the revaccinated birds having the greater 

 percentage of dead germs and the lower hatchability. After hatching, all 

 chicks were placed in isolated groups for vaccination at one day of age and 

 seven days of age. Under isolated conditions, as described, they all survived 

 vaccination with the modified live virus wing web Newcastle vaccine. 



Therefore, under these conditions, from the limited scope of this ex- 

 periment, there are indications suggesting the possibility of vaccinating chicks 

 under 4 weeks having parental immunity with the Newcastle modified live 

 virus wing web vaccine without anticipating too great a mortality. 



W. R. Dunlop 



Artifical Light Delays Pullet Maturity. 



The common complaint that replacement chicks hatched in the fall 

 mature early and lay more small eggs can now be overcome by proper appli- 

 cation of artificial light. The reason that light is effective is that it is applied 

 during the entire, growing period. Used during the fall and winter period 

 of short days, the light voids the stimulation normally provided in the spring 

 by the. increase in natural daylight. It is this increase in natural daylight as 

 the pullets approach maturity that causes the early sexual maturity and re- 

 sulting small egg size. 



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