Three selected South African Ornithobacterium rhinotracheale field isolates were identified and inoculated
via the caudal abdominal airsac into 28-day-old broilers, which were monitored under controlled
laboratory conditions. It was concluded from data that the O. rhinotracheale isolates were capable of
causing primary disease, with statistically significant resultant mass loss. Respiratory and arthritis symptoms
were reproduced. However, no sinusitis was observed.
Airsacculitis- and arthritis-lesion scoring techniques showed significant pathogenicity differences between
isolates. Furthermore, differences in symptomatology were also seen between isolates. A highly
significant reisolation of O. rhinotracheale was made from the brains of broilers challenged with isolate
In conclusion, the economic importance and financial loss due to Ornithobacterium rhinotracheale
infections in poultry were highlighted.
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