Observations on host range and control of goose virus hepatitis.
A number of experiments were done with a strain of goose hepatitis virus (isolated from sick goslings in the Netherlands in 1969. This virus was easily grown in embryonating eggs of the Muscovy duck (Cairina moschata) as well as in embryonating goose eggs. It also proved possible to adapt it to White Pekin duck eggs. The susceptibility of embryonating eggs obtained by crossing Muscovy drakes with Pekin ducks was intermediate between that of eggs from the two parental breeds. It was not possible to adapt goose hepatitis virus to growth in chicken embryos. The sensitivity of goslings to the goose hepatitis virus was found to vary considerably according to the farms from which they came. These differences were caused by variations 'in the quantity of parentally derived antibodies. One day-old Muscovy ducklings appeared to be at least as sensitive to the virus as goslings. However, disease symptoms could not be produced with goose hepatitis virus in Pekin ducklings nor in ducklings obtained by crossing Muscovy drakes and Pekin ducks. Treatment with homologous immune serum protected susceptible goslings and Muscovy ducklings against the disease. Under farm conditions, mortality was reduced from 30 to 3%. A breeding flock of adult Muscovy ducks, which had by serum therapy survived a goose hepatitis infection at an early age, produced ducklings resistant to the goose hepatitis virus. Over 100 flocks of geese, totalling more than 6,000 birds, were actively immunized with goose hepatitis Virus. The progeny produced in the following breeding season resisted, almost without exception, a challenge at one day of age with virulent goose hepatitis virus.
Hoekstra
J
J
Poultry Department, Central Veterinary Institute, The Netherlands.
Smit
T
T
Van Brakel
C
C