Abstract:
Oxytetracycline is used to treat various diseases in cattle. However, its use may be associated
with unacceptable residue levels in food. Oxytetracycline residues in tissues from indigenous
cattle were determined in a cross-sectional study conducted in the Kilosa district, Tanzania,
between November 2012 and April 2013. A total of 60 tissue samples, including muscle,
liver and kidney, were collected from slaughterhouses and butchers and analysed for
oxytetracycline using high-performance liquid chromatography. Oxytetracycline residues
were found in 71.1% of the samples, of which 68.3% were above acceptable regulatory levels.
The mean concentration of oxytetracycline across tissues was 3401.1 μg/kg ± 879.3 μg/kg;
concentrations in muscle, liver and kidney were 2604.1 μg/kg ± 703.7 μg/kg, 3434.4 μg/kg ±
606.4 μg/kg and 3533.1 μg/kg ± 803.6 μg/kg, respectively. High levels of oxytetracycline
residue in meat from indigenous cattle may pose a health threat to consumers in Kilosa.
The findings possibly reflect a general lack of implementation of recommended withdrawal
periods, ignorance about drug use and lack of extension services. Strict regulation of the use
of antimicrobial drugs in the livestock industry and associated testing of animal-derived food
sources prior to marketing are required.
