Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/3/2004
Publication Date: 10/3/2004
Citation: Reyes-Herrera, I., Schneider, M.J., Cole, K., Blore, P.J., Donoghue, D.J. 2004. Variations in antibiotic residue concentrations between different muscle tissues in poultry. Meeting Abstract.
Technical Abstract: The use of veterinary antibiotics is an important tool for the treatment of disease in poultry. However, misuse of these antibiotics can create antimicrobial residues in edible animal tissues exceeding the FDA established safety tolerances. To ensure the safety of the U.S. food supply, the Federal Government monitors foods, including poultry, for illegal residues. For the veterinary antibiotic, enrofloxacin (Baytril), the FDA, in the Code of Federal Regulations, has listed muscle as the tissue to be monitored in poultry irrespective of the type of muscle tissue. This study was conducted to determine if either breast or thigh meat is a better indicator of the highest enrofloxacin concentrations. One hundred and sixty five, 5 wk-old chickens were dosed with the FDA approved dose of enrofloxacin in water. The 4 treatment groups were: 25 ppm for 3 days, 25 ppm for 7 days, 50 ppm for 3 days or 50 ppm for 7 days. Five chickens from each treatment group were randomly selected and samples of breast and thigh muscle tissue were collected prior to dosing (controls n=5), during the dosing (n=5/group/day) and for a 3-day withdrawal period (n=5/group/day). Each sample was prepared and assayed using an agar diffusion microbiological method (Schneider and Donoghue, Poultry Science 2004). The results demonstrated that greater overall concentrations of enrofloxacin were present in breast versus thigh muscle tissues during the dosing period (443±22 ppb vs. 386±24 ppb P<0.05). These data indicate that, at least for enrofloxacin, not all muscle tissues incorporate antibiotics at the same concentrations. Therefore, these results will provide assistance to the Federal Government and others in making decisions on how best to monitor muscle tissues to ensure established safety tolerances are not being exceeded.