Evaluation of maternal antibody levels for establishing the vaccination program against Newcastle disease in ostrich chicks

ABSTRACT Newcastle disease virus (NDV) is known as one of the most important endemic viral pathogen for various avian species such as ostrich, in Iran. Therefore, establishing a routine vaccination program against ND in ostrich flocks would be useful in order to reduce the danger of this infection. Newcastle disease occurs among the ostriches and leads to high rate of mortality while most of the losses are among the youngest ones. This experiment was designed to follow up the changes of maternal antibody in ostrich chicks during the first weeks of their life. At this point of view, 700 one day old ostrich chicks were monitored and every seven days interval 10 blood samples were taken regularly and the titers of maternal antibody in their sera were studied. The haemagglutination inhibition (HI) test was used to evaluate the amount of anti-ND antibody. After hatching this study followed up to 49 th day. Due to our findings, the day 30 is recommended as a proper time to start the vaccination program against ND in flocks of ostrich chicks with maternal antibody

Isolation of Ornithobacterium rhinotracheale from the brains of commercial broiler breeder chickens with meningitis and encephalitis

Ornithobacterium rhinotracheale (ORT) has been identified as one of the respiratory bacterial pathogens in turkey and chicken flocks. Four live birds displaying severe torticollis were submitted from a 13-week-old commercial broiler breeder chicken flock located in Mazandaran province. These birds were suspected to pasteurellosis by the farm veterinarian. No other marked gross lesion except emaciation was seen. Histopathologic examination of the brains showed mild to moderate meningeal vasculitis, perivascular cuffing with lymphocytes, degeneration and necrosis of purkinje cells in the cerebellum. Viral culture of the brains especially for Newcastle disease and avian influenza viruses was negative. Bacterial culture of the brains onto the blood agar revealed pure growth of Ornithobacterium rhinotracheale. In this study molecular confirmation of ORT by using of a very specific polymerase chain reaction (PCR) was carried out. Amplification products of a 784 bp region of the 16S rRNA gene of ORT confirmed the bacterium identification. This is the first field case of ORT isolation from the brain of commercial chickens in Iran. These data suggest that this bacterium should be considered in differential diagnosis in cases of avian nervous signs. Further studies are necessary to confirm if ORT is a primary pathogen in such cases