Infectious bronchitis is a highly contagious disease and considered as one of the most important and common poultry diseases and it causes huge economic losses in poultry industry due to its effect on broiler growth and its effect on egg production quantity and quality in adult hens. Inactivated vaccines are important component in vaccination program for layer and breeder for protection against egg production and also provide early protection against infection through maternal immunity in progeny. This study was conducted to compare the efficacy performance between prepared bivalent IB inactivated vaccine and commercial one in commercial layer chickens, vaccinated chickens from both groups were challenged for evaluation of both homologous and heterologous protection, and all these steps were compared with control non vaccinated groups. Enzyme linked immunosorbent assay (ELISA) was used for estimation of humoral immunity and also transmissible maternal immunity through laid egg yolk post vaccination from all groups, challenge strains were detected by using Real-Time RT-PCR from tracheal and oviduct samples in all groups and also histopathological changes were evaluated after challenge test from collected samples. The results revealed that the prepared vaccine give higher protective antibody titer in both serum and egg yolk as commercial vaccine which provided good protection against both homologous and heterologous challenge with comparison in control groups. Post challenge changes in trachea and oviduct samples take good evaluation in vaccinated groups with histopathological techniques. This confirms that under field condition, poultry industry can be protected from IB disease if using locally prepared inactivated vaccine as look like imported commercial one in Egyptian layer farms. |
