Inappropriate usage of selected antimicrobials: Comparative residue proportions in rural and urban beef in Uganda

INTRODUCTION: In most developing countries like Uganda, antimicrobials including β-lactams and tetracyclines are used indiscriminately in livestock. When livestock get sick and treatment is necessary, some producers and veterinarians use these drugs with minimal controls to prevent residues from occurring in the beef sent to markets. This study was done to determine the presence of drug residues above acceptable limits of two commonly used antimicrobials in Uganda’s rural and urban beef. METHODS: A cross-sectional study was conducted of 134 cattle carcasses from eight different slaughter slabs over twelve weeks. This study entailed 81 samples of rural and 53 samples of urban origin. To enable detailed analysis these samples were categorized according to age (maturity), breed, and sex. For each of the 134 carcasses, three samples of liver, kidney and muscle were taken and homogeneously mixed into one sample, which was tested for β-lactam and tetracycline drug residues. RESULTS: The results were statistically significant for β-lactam levels (χ(2) = 22.10, df = 10, p = 0.0146) with average concentration (μg/kg) of 2.93:29.3 (rural: urban), though not for tetracycline levels (χ(2) = 3.594, df = 10, P = 0.9638) with average concentration (μg/kg) of 5.028:12.83 (rural: urban). Age (maturity) had significant effect at all values of antibiotic level (F((1, 68)) = 5.06, p = 0.0278). Age effect was extremely significant (F((1, 68)) = 15.51, p = 0.0002). CONCLUSION: A significant difference existed in drug residue proportions of β-lactam and tetracycline antimicrobials among Uganda’s rural and urban beef. A significant difference also occured in drug residue proportions of these two commonly used antimicrobials related to age (maturity), but neither breed, nor sex, of Uganda’s rural and urban beef.