A contribution to the study of Newcastle disease congenital immunity in chickens

Foi investigada a presença de anticorpos congênitos da doença de Newcastle (DNC) no soro e no saco vitelino em pintos recém-nascidos e verificou-se que os anticorpos da DNC presentes no soro diminuem a partir do 7.° dia e no saco vitelino a partir do 5.° dia de vida. Em pintos com imunidade congênita, vacinados com vacina viva, o título de anticorpos inibidores se mostrou mais alto quando vacinados a partir do 8.° dia do que quando vacinados nos primeiros dias de vida.The presence of congenital antibodies of Newcastle disease (DNC) in serum and in the vitelline sac of newborn chickens was investigated. It was found that the decrease of DNC antibodies present in serum starts after the 7th day of life and in the vitelline sac the decrease occurs after the 5th day. In chickens with congenital immunity, inoculated with attenuated virus vaccine, the content of inhibiting antibodies was higher when inoculated after the 8th day and lower when inoculation was made during the first days of life