Determination of Tetracycline Antibiotic Residue in Dairy Products Sold in Ogbomoso, South-western Nigeria

This study investigated the levels of the antibiotic tetracycline contained in cow milk, goat milk, butterfat, soft cheese and yoghurt samples. High performance liquid chromatography (HPLC) standard methods were used for the detection and quantification of tetracycline in 40 dairy products samples. All the analysed samples contained residues of tetracycline antibiotics. The mean tetracycline residual levels were as follows: 0.0032 ± 0.0018 ppm (cow milk); 0.0040 ± 0.0011 ppm (goat milk); 0.0020 ± 0.0008 ppm (butterfat); 0.0080 ± 0.0034 ppm (soft cheese) and 0.0019 ± 0.0008 ppm (yoghurt). The level of the tetracycline antibiotic in soft cheese was significantly (P<0.05) higher than those for cow milk, goat milk, butterfat and yoghurt, whose values were similar (P>0.05). The detection of tetracycline residues in all of the tested samples revealed that the processing of cow milk into milk products did not eliminate the tetracycline antibiotic. The observed tetracycline residue levels in the dairy products were below the maximum residue level (MRL) of 0.1 ppm (European Union (EU) standards and were thus safe for human consumption. The government however needs to enforce continuity in the adherence to the tetracycline and other drug maximum residue limits at all times in the dairy industry in Nigeria in order to protect the health of consumers.