Comparative studies of serum neuraminidase, free and erythrocytes surface sialic acid, packed cell volume and haemagglutination inhibition antibodies of chickens vaccinated with different Newcastle disease virus vaccines

Abstract

Comparative studies of serum neuraminidase, free and erythrocytes surface sialic acid, packed cell volume and haemagglutination inhibition antibody titres were carried out on a total of seventy-five Shaver Brown chickens that were vaccinated with different Newcastle disease virus (NDV) vaccines. Trial birds were primed with NDV Hitchner B1 vaccine prior to NDV La Sota and NDV Komarov vaccines administration. Twenty-five chickens received NDV La Sota vaccine; a further 25 were vaccinated with NDV Komarov vaccine, while 25 chickens served as control. The values of neuraminidase activity (NA), free serum sialic acid (FSSA), erythrocytes surface sialic acid (ESSA) concentration, packed cell volume (PCV) and haemagglutination inhibition (HI) antibody titres were determined sequentially for each chicken. The highest daily mean HI antibody titres of log2 7.12 ± 1.20 and log2 8.98 ± 1.73 were obtained from chickens vaccinated with NDV La Sota vaccine and NDV Komarov vaccine, respectively, by day 15 post-vaccination (pv). Neuraminidase activity and FSSA concentration increased gradually from days 1 to 5 pv in the two groups of chickens. In general, the period of increased NA and FSSA concentration coincided with the time of a decline in values of ESSA and PCV in the two vaccinated groups of chickens. It was concluded that chickens which received NDV Komarov vaccine had higher daily mean values of NA, FSSA and HI antibody titres than their counterparts which received NDV La Sota vaccine