Comparative assessment of commercial and local prepared Salmonella vaccines against Salmonella infection in Duckling

This experiment was conducted to assess the efficiency of the commercial Servac trivalent inactivated Salmonella bacterin in comparison with the prepared inactivated S. Infantis oil emulsion bacterin against Salmonella infection. A total of 70 Muscovy ducklings (one day old) were divided into 3 groups each containing 20 ducklings, except the control group which contained 30 ducklings. Groups 1 and 2 were vaccinated with commercial Servac trivalent inactivated Salmonella bacterin, (consisting of S. Typhyimurium, S. Kentucky, and S. Enteritidis), and the locally prepared S. infantis inactivated bacterin respectively, at 7 days of age subcutaneously (0.5 ml/duckling) and boostered by the same dose and route at 22 days of age. Both groups were subdivided into G1a, G1b, G2a, and G2b at 37 days of age for oral challenging (1ml containing 17× 109 CFU) of S.Typhyimurium (G1a, G2a) and S. Infantis (G1b.G2b), while group 3, (control group) sub-grouped into G3a (infected with S.Typhyimurium unvaccinated) , G3b (infected with S. Infantis unvaccinated), and G3c which kept as the negative control group. Signs, postmortem lesions, mortalities and fecal shedding were evaluated to detect the protection percentages of the vaccinated groups post-challenging. Reduced fecal shedding, Salmonellae recovery from internal organs, absence of signs and postmortem lesions were noticed compared with control positive groups. The candidate prepared and commercial Servac bacterins could provide ducks with 100% protection against Salmonellae infection without any significant difference.