Incidenc on commercial farms of duck virus hepatitis in White Pekin ducklings hatched from immunized and unimmunized dams.
D000818:Animals; D004372:Ducks; D006518:Hepatitis Viruses; D006520:Hepatitis, Animal / Q000517:prevention & control*; D007109:Immunity; D011201:Poultry Diseases / Q000517:prevention & control*