Research studies septicemia/toxemia disposition in broilers

Septicemia-Toxemia (septox) is the largest and most costly FSIS category for whole bird carcass condemnations in the US. Paws from these condemned carcasses are required to be removed, which necessitates disposal of many normal paws. So, even slight reductions in condemnations can result in large economic gains for poultry companies.

Since E. coli is the most common bacteria pathogen causing septicemia in broilers in the field, colibacillosis was the model used in this study to assess the effects of septicemia in the broiler carcass.

Objectives
–           To provide a more precise microscopic and macroscopic description of changes in the broiler carcass following experimentally induced colisepticemia
–           To document any organ/tissue changes in whole birds condemned for septox
–           To compare the two groups’ (experimental and processing plant) microscopic and macroscopic lesions  
–           To provide a more critical, scientific description of the septox disposition criteria

The results of this study indicate that the birds challenged with E. coli had acute, gross lesions of hepatomegaly, splenomegaly, synovitis and osteomyelitis, as well as certain microscopic lesions such as fibrinous exudate in splenic follicles and marked elevations in the numbers of heterophils in the bone marrow. Septox condemned carcasses were typically smaller carcasses with muscle wasting, skin discoloration, and dehydration. Common histologic changes in septox carcasses included spleen follicular histiocytosis and liver cholangitis. Increased bone marrow cellularity was also confirmed in many condemned carcasses, but at a much lower level than in the experimentally challenged birds.

These findings indicate that the typical septox carcasses do have gross and microscopic pathology indicative of some type of chronic systemic effect, but this should not be interpreted to mean the septox carcasses are actually septic.

This study affirms the need to correlate the gross and microscopic pathology to the microbiological status of the condemned carcasses. This would confirm the presence or absence of sepsis as well as help document whether the septox changes are a public health risk. This study also introduces histomorphometrics as a potential tool for use in scientifically evaluating systemic, microscopic changes in chickens. This methodology could be used to help evaluate certain disposition criteria established for inspectors. In view of economic and food safety issues, this data should add some scientific impetus to continue investigations to help determine the wholesomeness of septox carcasses.

*The research: “Septicemia/Toxemia Disposition in Broilers: Increasing Accuracy Within Current Regulations”
Timothy S. Cummings, D.V.M., M.S., A.C.P.V.; Floyd Wilson, B.S., D.V.M. College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, and Marty Ewing, D.V.M., M.A.M.; Mark Burleson, D.V.M., M.S., Sanderson Farms, Inc., Laurel, MS, and Fred Hoerr, D.V.M., Ph.D., A.C.V.P., A.C.P.V., State of Alabama Diagnostic Laboratories,
Auburn, AL.