| Dissertation note |
This study trial was designed to evaluate and compare the efficacy of two locally available live Newcastle disease vaccines (Medivac ND LaSota and VRI, Mukteshwar ND vaccine), also to compare two routes (Oral and Ocular) of vaccine administration in term of antibody titre and assessment of protection against field (chicken) isolated virulent Newcastle virus challenge (NDV) in pigeons. Study of clinical signs, gross and histopathological lesion in different organ of non-vaccinated and challenged birds was also the part of our present study. For this purpose one hundred and twenty pigeons were purchased from the local market and screened for Newcastle disease antibodies using Hemagglutination inhibition test. Healthy pigeons were randomly divided into six groups i.e. A, B, C, D, E and F, comprising 20 birds each. Group E and F were kept as positive and negative Control respectively. Group A and C were vaccinated with Medivac ND LaSota vaccine at day 7th and 21st of experiment through oral and ocular route. Similarly Group B and D were immunized with VRI (Mukteshwar) ND vaccine through oral and ocular route respectively. At 28th day of experiment all the groups except group F were challenged with velogenic field isolate of NDV at a dose rate of 0.1 ml through ocular route. Serum samples were collected at day 14, 21, 28, 35 and 42 of experiment for the determination of antibody titre. Post-infection clinical signs in control positive group were i.e. anorexia, dullness, depression, decreased feed intake, discharge from mouth, greenish diarrhea, nervous manifestations, leg and wing paralysis. Gross lesions on different organs were hemorrhages in trachea, proventriculus, spleenomegaly and greenish intestinal contents. Medivac ND LaSota vaccine produced higher immune response in term of antibody titre as compared to VRI (Mukteshwar) ND vaccine. It was also observed that ocular route irrespective to vaccine type produced significantly (P<0.05) higher immune response than oral route. Vaccine strains used in this study efficiently induced immune response through ocular route, suggesting that implementation of this vaccination programs in future may prevent ND outbreaks in pigeons, especially in racing pigeons, and may prevent NDV spread to other avian species, mainly poultry.
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