“…Vaccination for protecting chicken from ND is routinely practiced throughout the world, but the vaccination is ineffective with the high titer of maternal antibodies (2,3). In birds the maternal antibodies in the egg is manifested by three classes of antibodies in chicken namely IgY, IgA and IgM (4-6), IgY is present in the egg yolk whereas IgA and IgM are present in the egg white as a result of mucosal secretion in the oviduct, the transfer of IgY from the dam to her offspring takes place in a two step process in the first step IgY is taken up into the egg yolk by IgY receptors on the ovarian follicle from the dam's blood through the granulosa cells in the second step IgY is transferred from the egg yolk to the offspring via the embryonic circulation (4,(6)(7)(8). This type of immunoglobulin is act as passive immunity because these antibodies are derived from the dam and protect the offspring from various infectious disease (9).…”