Comparative efficacy of avinew (VG/GA strain) and BCRDV (F strain) vaccines against Newcastle disease in broiler chickens

Abstract

A study was conducted for the detection of persistence of maternal antibody as well as the comparative efficacy of Avinew (VG/GA Strain) and BCRDV (F Strain) vaccines against Newcastle disease during the period from January to April 2006 using 100 day-old broiler chicks divided into three groups namely A, B and C. Birds of groups A and B consisting each of 40 were primarily vaccinated intraocularly (IO) with Avinew and BCRDV respectively at the age of day three (3) and secondarily with the same vaccines, as the cases were, on day 20. Sera samples were obtained from 10 randomly selected birds on each occasion of day 1, 10, 17, 27, 30, 34 and 44 of age of birds. Birds of group C were maintained as unvaccinated control for the determination of existence of maternal antibody parallel to the day of vaccination and challenge. It was observed that following primary vaccination in case of group A, the HI titres with a mean ± SD on day 10 and 17 were 121.6 ± 19.2 and 60.8 ± 9.60 respectively as against at mean titres ± SD of 57.6 ± 12.8 and 30.4 ± 4.80 in case group B respectively. On the other hand, subsequent to secondary vaccination, sera samples obtained from group A on day 27 had a mean ± SD of HI titres 128 ± 0 and in case of group B, the performance of Avinew in respect of such titre was 57.6 ± 12.8 on day 27. Thus it was indicated that performance of Aninew in respect of elucidation of HI antibody was comparatively better than that of BCRDV. In case of unvaccinated control birds of group C, the mean of existence of maternal antibody with ± SD were 512 ± 0, 54.4 ± 14.66, 24 ± 8, 12.8 ± 8.54, ⤠4, ⤠4 and ⤠4 at the age of day 1, 10, 17, 27, 30, 34 and 44 respectively. One half of vaccinated birds of groups A and B were subjected to challenge test with a virulent isolate of NDV on each of two occasion of day 30 and 44 of age of birds where it was observed that 100% of both the groups of A and B were refractory to each test whereas 95% and 85% of the remaining half of birds of groups A and B resisted the challenge exposure. It was found that maternal antibody against NDV in chicks persisted to a minimal until the age of day 27 and none at day 30 or 34. The analysis of HI titres by Student's t-test revealed that Avinew vaccinated group maintained significantly higher HI titres following primary and secondary vaccination as well as during first challenge than that of BCRDV vaccinated group.

Key words: Avinew, BCRDV, efficacy, vaccine, broiler chicks  

DOI = 10.3329/bjvm.v5i1.1304

Bangl. J. Vet. Med. (2007). 5 (1 & 2): 19-23