Studies on The Problems of Postvaccination Reactions Resulting from Newcastle Disease Vaccines

1.Vaccination of day and one week-old-chicks vd th the Hitchner Bl-strain in the drinking water did notinduce any detectable undesiarable post-vaccination reactions. However application of the vaccine viaspray method to vaccinate both ages,of chicks, ’induceda mild and transiant respiratory reactions on day old chf.cks only and there ’were no losses among all vac c ina- ted birds.2.Hi tchner Bl vaccine when used via the drinking water for the vaccination of day or week-old-chicks infected withpathog~nic E;coli induced a mild-transiant post-vaccin- ation respiratory zeac.t Lona in a few number of birds with 10 - 5 % losses among them respectively.J 0 Vaccination of day old chicks wf.t h the La Sota vaccine in the drinking water resulted in an evidenced post-vaccination reactions of the respirfltory type in a few•number of birds ccn t Lnued for 2 to :3 day s and a 55 mortality rate among them. On the other hand vaccina-tion of one week old-chicks with the same vaccine and route of application, induced a ,slie;ht-transiant respi-ratory reactions without losses among the birds.