Effect of intensive vaccination against Newcastle disease on the immune response in broiler chicks
1989
Ali, D.S.
Three groups of broiler chicks were vaccinated with the Lasota strain of Newcastle disease virus, at 10 and 20 days of age (group 1), 10, 20 and 30 days of age (group 2), 10, 20, 30 and 40 days of age (group 3). Hemagglutination -inhibition (HI) antibody titers were measured at 20, 30, 40 and 51 days of age in individual chicks of all groups. Virus - neutralization (Vn) antibody titers were measured at 20,30,40 and 51 day of age in individual chicks of group 3. The HI and Vn antibody titers were measured after one day of each vaccination in individual chicks of group 3. After the first vaccination the HI titers were low in chicks of all groups, and after the second vaccination the HI titers increased in all groups. After the third vaccination of groups 2 and 3 the HI titers increased only in vaccinated chicks with the HI titers of 32 units or Less.
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