Estimating serological immune response against Newcastle disease vaccine in Aseel, Kadaknath and White Leghorn chicken by haemagglutination inhibition test.

The present study aimed to estimate serological immune response against Newcastle disease vaccine investigating 70 Aseel, 75 Kadaknath and 85 White Leghorn chicks. The day-old chicks were vaccinated with a dose of 10^6.5 EID₅₀ of RDF₁ strain through occulo-nasal route followed by a booster dose on 28^th day. The sera collected on 7, 14, 21, 28, 35 and 42 days post-immunization (dpi) were used to measure antibody titres through haemagglutination inhibition test. The data were analyzed by analysis of variance using SPSS 16.0 statistical software. The corresponding mean antibody titre (log2) estimates were 8.10±0.22, 7.89±0.18, 7.92±0.16, 8.29±0.14, 8.40±0.16 and 8.94±0.19 in Aseel, 7.32±0.16, 7.74±0.13, 7.56±0.13, 7.86±0.17, 8.43±0.17 and 9.14±0.16 in Kadaknath, and 8.48±0.28, 8.02±0.31, 8.29±0.33, 8.14±0.30, 7.68±0.29 and 7.73±0.29 in White Leghorn chicken. The estimates significantly varied among different dpi in Aseel and Kadaknath chicken except White Leghorn. Aseel and Kadaknath chicken demonstrated gradual increasing trend and higher means of antibody titres for longer periods of dpi and achieved the highest at 42 dpi, whereas White Leghorn chicken showed an irregular trend, the highest titre being observed at 7 dpi. Again the 3 chicken genotypes significantly varied in antibody titres at 7, 35 and 42 dpi; White Leghorn chicken demonstrated the highest antibody titre at 7 dpi, while Kadaknath chicken showed the highest titre at 35 and 42 dpi. The higher and longer immune responsive Aseel and Kadaknath chicken might be utilized for selective introgression of their candidate genes in high productive chicken germplasm with less NDV response. [ABSTRACT FROM AUTHOR]