Journal of Microbial Pathogenesis

Fowl typhoid is one of the most significant bacterial diseases of layer birds. Its significance is drawn from the cost of productivity in commercial layer poultry. Vaccination is a superlative way of preventing disease in commercial poultry. In the current study, immunization, and protective efficacy of local strain in a prepared autogenous bacterin had been studied. A total of 120-layer birds of crystal neck breed were equally divided into three groups (A, B and C) having 40 birds in each. The birds of group A were kept as negative control (non-infected and non-treated), the group B was kept as a positive control (challenged with Salmonella gallinarum and non-treated) and group C was kept as a vaccinated group (challenged and vaccinated). All the experimental groups were retained under surveillance for the 3^rd-week post-challenge. The protection assay was evaluated according to the clinical signs, mortality, fecal shedding of challenged birds. On weekly basis, the blood was collected and humoral immune response against Salmonella gallinarum was assessed by using Micro-agglutination Test (MAT) and ELISA. The results showed that autogenous bacterin increases the performance of chickens by reducing clinical signs, mortalities, gross lesions, and fecal shedding. The local bacterin increased the humoral immune response in the vaccinated group (C) as compared to the positive control group (B). In conclusion, the locally prepared autogenous bacterin protects against challenged infection of Salmonella gallinarum.