DETERMINATION OF OXYTETRACYCLINE RESIDUE LEVELS IN EDIBLE TISSUES OF SLAUGHTERED CATTLE

Abstract

Worldwide, antimicrobials are widely used in food producing animals for treatment and/or prophylaxis of diseases. In Tanzania, irrational administration of antimicrobials, notably oxytetracycline (OTC) is common because of the under-developed animal health service delivery system. The administration of OTC and other drugs is often done by animal keepers, thereby leading to drug residues in meat and milk. The study established the level of OTC residues in edible tissues of cattle slaughtered within Dodoma City Tanzania. This was cross-sectional analytical study design which quantified drug residues in muscle, liver, kidney from licenced and unlicenced premises. Samples from licenced as well as unlicenced premises were collected and used in determining OTC levels using High Performance Liquid Chromatography (HPLC) method. The HPLC method was validated to establish the reliability of the method in quantifying OTC residues. The results indicated that OTC residues were 0.6 mg/kg, 0.25mg/Kg and 1.28 mg/kg for muscle, liver and kidney tissues, respectively against corresponding Maximum Residue Limit (MRL) 0.2mg/kg, 0.6mg/kg and 1.2mg/kg. Regardless of the licensure status and source of the sample, 53% of muscle, 65% of liver and 7.1% of kidney tissues were above MRL. The quantities of OTC residues in samples from licensed and unlicensed food vending settings were not significantly different (p = 0.3676) but above the MRL. The above results show unacceptably high levels of OTC residues in meat with most beef value chain actors being ignorant of the impending public health threat/risks of consuming beef with high drug residues.