The Animal Health Research Center - University of Georgia College ...

Bacterial and
Parasitic Diseases
Clinical Investigation of Poultry Diseases
Two studies were completed under this project. The first was to determine is there is a potential interaction between turkey coronavirus
and reticuloendotheliosis virus. The objective of this experiment was to co-infect SPF turkeys with turkey coronavirus and reticuloendotheliosis
virus obtained from field cases to determine if there is a potential interaction between the two. Body weights of the
experimental groups were compared to controls to determine weight reduction after infection. The digestive tract and immune system
tissues were examined microscopically for lesions. RT- PCR was performed on intestinal contents of individual turkeys to detect the
presence of TCV RNA and to assess virus persistence in the gut. Virus isolation was performed from plasma to demonstrate viremia
induced by REV. The combination REV-infected and TCoV-infected birds suffered more severe weight depression than the control
birds or the birds infected with REV or TCoV alone. Viral persistence in the gut was variable.
The second study involved the investigation of alternative routes (oral, eye drop or wing web) of vaccination in poultry. Broiler breeder
pullet vaccination for fowl cholera via wing web route is costly due to labor and can result in stress and injuries to vaccinated birds.
Pullets vaccinated with live vaccine by wing web route also risk acquiring the disease contributing to joint problems, morbidity, and
death. Therefore in 2004, in an effort to investigate alternative routes of vaccination, Bruzual et. al, evaluated the use of a commercial
Pasteurella multocida PM-1 vaccine administered by the drinking water in broiler breeder pullets versus administration by wing web.
It was concluded that there was no protection by administration of a 6X dose of PM-1 orally in pullets whereas those given the vaccine
by the w.w. route were protected. In this investigation, oral, eye drop, and wing web vaccination will be evaluated using the less attenuated
CU (Clemson University) strain of Pasteurella multocida. Both post-vaccination mortality and post-challenge mortality after
inoculation with a highly virulent serotype 1 Pasteurella multocida will be compared between treatment groups vaccinated orally, by
eye drop, and via wing web with the CU strain and a group vaccinated with a commercial PM-1 strain via wing web application.