Antibody level against Newcastle disease virus in commercial layer flocks.

摘要

40 blood samples were collected at 0, 4 and 8 weeks of age in ten commercial layer flocks. The day-old-chick showed high levels of maternal antibody with GM values ranging from 48.5 to 194.0. The HI titre at four weeks of age before administration of LaSota and at eight weeks of age were found to be very low, most of the birds showed nil titre indicating a lack of circulating antibody response to NDVF vaccine given at 5-7 day of age and LaSota vaccine given at four weeks of age.