Antibiotic residues in cattle reported to be raised without antibiotics

Authors: Lehotay, Steven; MICHLIG, NICOLAS - Oak Ridge Institute For Science And Education (ORISE); LIGHTFIELD, ALAN - Retired ARS Employee; DOMESLE, ALEXANDER - Food Safety Inspection Service (FSIS); WIGGINS, SABRINA - Food Safety Inspection Service (FSIS); DUVERNA, RANDOLPH - Food Safety Inspection Service (FSIS); WEYRAUCH, KATIE - Food Safety Inspection Service (FSIS)

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2024
Publication Date: 1/8/2025
Citation: Lehotay, S.J., Michlig, N., Lightfield, A., Domesle, A., Wiggins, S., Duverna, R., Weyrauch, K. 2025. Antibiotic residues in cattle reported to be raised without antibiotics. Journal of Agricultural and Food Chemistry. https://doi.org/10.1021/acs.jafc.4c07440.
DOI: https://doi.org/10.1021/acs.jafc.4c07440

Interpretive Summary: For the sake of labeling integrity and economic competitive fairness, label claims need to be truthful with regard to products from animals said to be raised without antibiotics (RWA). In 2022, a study reported that urine samples from 15% of RWA cattle at a slaughter establishment in the US contained detectable levels of antibiotic residues. In collaboration with FSIS, the ARS scientists analyzed for 185 veterinary drugs in kidney and liver samples from 189 RWA cattle collected from across the US. Sophisticated methods of analysis were used to identify, quantify, and confirm any of the monitored drug residues in multiple samples. In all, 20% of the RWA animals were confirmed to contain ultra-trace residues of antibiotics commonly used for treatment of illnesses in cattle. FSIS is following up with producers to further investigate the causes of the findings, and possible changes in RWA policies and production practices are being considered.

Technical Abstract: In 2019, the USDA Food Safety and Inspection Service (FSIS) provided revised guidance for labeling claims of “raised without antibiotics” (RWA) and similar terms for meat and poultry produced in the US. In 2022, a study was published reporting that 15% of RWA-labeled cattle contained antibiotic residues in urine samples. In 2023, the USDA embarked on this project to independently determine the extent of antibiotic drug residues present in kidney and liver tissues from slaughtered cattle purported to be RWA. FSIS inspectors randomly collected kidney and liver tissues from 189 RWA animals in 78 slaughter establishments across the US. The samples were monitored for 185 veterinary drugs multiple times by different means, including liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS) and quadrupole high-resolution MS with an orbital ion trap instrument (LC-Q/orbitrap). Samples from 37 animals (20%) met the analytical identification criteria for at least one antibiotic confirmed in at least two analyses. Multiple antibiotics were determined in 11 RWA animals. Macrolides (tulathromycin, tildipirosin, tilmicosin, and gamithromycin) were confirmed in 20 (11%) of the RWA animals. The ionophore, monensin, was also confirmed in tissues from 11 samples, with unconfirmed/partial identifications in 8 others. Tetracyclines were confirmed in samples from 12 animals, several of which were found to contain multiple antibiotic residues. One animal each was also found to be positive for sulfamethazine (a sulfonamide antibiotic) and metabolites of penicillin G (a ß-lactam antibiotic). Although they are not antibiotics, two anthelmintics (fenbendazole and eprinomectin) were confirmed in tissues from 3 RWA animals. FSIS is following up with slaughter establishments and producers to help determine possible sources of the residues found.