The Resistance to Marek’s Disease of Chicks from Immunized Breeders

PARENTAL antibodies from dams immunized to the visceral lymphomatosis virus (V.L.V.) have been shown to give protection to chicks challenged with V.L.V. (Burmester, 1955). It is common practice today to vaccinate breeding stock for avian encephalomyelitis. This results in an immunity in the breeder and a strong parental immunity transmitted to the progeny (Schaaf and Lamoreux, 1955; Calnek et al., 1961). The identification of the Marek’s virus as a separate entity from the V.L.V. virus (Churchill and Biggs, 1967) and the development of techniques for demonstrating antibodies to Marek’s disease (Chubb and Churchill, 1968) has spurred attempts to produce a vaccine for use in young These same developments also suggest breeder stock might be immunized to Marek’s disease with a resulting parental immunity conveyed to the chick via the yolk material (Arbor Acres Review, 1968). The purpose of this study was to determine: 1. if breeders could be sufficiently immunized…