Incidence of some respiratory viral diseases in chickens in dakahlia province using agar gel precipitatin

1066 sera Were used to study the incidence of ND, IB and CELD in Dakahlia Province. Results obtainedcould be summarized in the [Fllowing 1-1 S, The use of agar gel technique to detect precip- itating antibodies in tested sera revealed the following percentage of positive reaotores:-ND._ 3.2%. IB 15.7%, CELO 5.62%~2 : The inci~ence of preoipitating antibodies against, these agents was higher in farms ~an individua birdS.3 ~ The occurrance of precipitating antibodies andhaemagglutinating inhibiting antibodies against ND proved to have higher percentage in birds withrespiratory manifestation than those apparently healthy. Similar influence was shown against CELO. but the antibodies against IB gave ,nearly the same level.4: Prec~pitating antibodies against IB showed bigherincidence than those of ND and CELO.