Clinical and serological examination of a parental flock latently infected with chicken anemia virus

At the beginning of etiopathogenic research on chicken anaemia virus (CAV) it was thought that groups of chickens at risk for CAV infection were those coming from a parental flock infected before laying. Therefore it is important to know the level and persistence of transfered maternal antibodies (MaAt) and to measure specific antibody development during rearing. The goal of this research was to assess the necessity for prophylactic measures by determining the humoral immune response to CAV and any clinical changes in breeder chickens. Chickens from the parental Hybro flock were examined from the first day until the end of production. Maternal antibodies for CAV, which were present initially, were not detected at 4 weeks old. At 6 weeks old specific antibodies for CAV were found in 45% of the serum samples. These antibodies increased until the 18th week when the experiment was terminated. The state of health of the parental flock in the period when MaAt antibodies could not be detected and until specific antibodies appeared did not differ significantly. The results of these investigations are the first evidence of CAV infection in Yugoslavia, based on serological examination.