Surveillance for Selected Bacterial and Toxicologic Contaminates in Carcass Meat Fed to Carnivores
Wildlife Safari, a zoo located in Winston, Oregon, has fed donated carcass meat as a diet to carnivores for 30 years. Carcass meat is an alternative to commercially prepared meat, which is used by many other zoological institutions.4,5 Donated meat arrives at Wildlife Safari as an entire animal. The entire carcass is fed out 10% of the time, while 90% of the time carcass meat is sectioned into measured diets. Despite the absence of problems associated with carcass meat at Wildlife Safari, this study explores techniques for improved monitoring of food safety. Prior to this study, Wildlife Safari has avoided toxicants in carcass meat by relying on medical treatment reports from owners or veterinarians associated with the donated animal. Animal carcasses that have systemic diseases or deaths due to unknown causes are also not used. Animals donated for meat consist of cattle, horse, deer, bison, elk and ponies.
As a supplement to the reported record of chemical treatment, 32 meat samples were analyzed offsite at Michigan State University’s Diagnostic Center for Population and Animal Health using gas chromatography/mass spectrometry screening.2 These samples were collected during a 3-month period ranging from November 2002 to January 2003. Levels of phenylbutazone, flunixin meglumine, and xylazine were monitored as potential toxicants. None of the meat samples were found to have evidence of these or arty other organic toxicants, suggesting that the records coming from the animal donors are sufficiently accurate for food safety.
In order to better monitor food-borne pathogens in a cost-efficient manner, Neogen Reveal® immunosorbent assays (Neogen Corporation, Lansing, Michigan 48912 USA) were performed onsite.6 Although the taxonomic range of monitoring was limited, immunoassays may establish a baseline of general safety associated with the carcass meat while still having the power to implicate specific pathogens. Testing of Salmonella spp., Listeria spp., and Escherichia coli O157:H7 was performed. Meat samples were collected from the left quadriceps region of each carcass for a 4-month period ranging from November 2002 to February 2003 (n=50). Twenty-five meat samples were randomly selected from this group to be included for the bacterial detection tests. The sensitivities and specificities of the Reveal® assays are comparable with those listed by the USDA/FSIS and the AOAC standards.1,3,7 Twenty-eight percent of the meat samples were positive for Salmonella ssp. (n=25). One sample was positive for Listeria spp. (n=25). None of the meat samples were positive for Escherichia coli 0157:H7 (n=25). As monitored, carcass meat appears to be a potentially safe food source for carnivores.
This project was supported by a grant from the Bureau of Land Management. The authors would like to thank John Flores and Leonard J. Schussel, PhD. The authors would also like to thank Josh Jones, Lisa Angland, and J. Bear for processing and collecting the meat for Wildlife Safari’s carnivores and this study.
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