Oxytetracycline residues in edible tissues of cattle slaughtered in Akure, Nigeria

Abstract

Meat and other edible tissues from slaughtered cattle from Akure metropolitan abattoir from January to June 2007 were analyzed with high performance liquid chromatography (HPLC) for oxytetracycline residue. The extraction was done using hydrochloric acid and acetonitrile for deproteinisation, while clean up was by liquid- liquid partitioning using dichloromethane and petroleum ether. Elution, detection and quantification were done on Lichrosorb RP–18 HPLC machine coupled with UV – detector. Out of a total of 180 beef samples analyzed during this study, 98 (54.44%) of the total samples had detectable levels of oxytetracycline residues from which 62(34.44%) had oxytetracycline residues at violative levels above the WHO/FAO maximum residue limits (MRLs). The mean residues for positive samples were 51.8ìg/kg, 372.7ìg/kg and1197.7ìg/kg for muscle, kidney and liver respectively. The standard deviations (SD) of residue in samples tested positive were 718.9ìg/kg, 366.8ìg/kg, and 90.53ìg/kg in liver, kidney and muscle respectively. These high level oxytetracycline residues in greater proportion of meat destined for human consumption at violative levels could be as a result of the indiscriminate use and misuse of veterinary drugs as commonly practiced among livestock producers and marketers without observing withdrawal period prior to slaughter. These results indicate that consumers may be predisposed to health hazards and hinder international meat trade from Nigeria. Regulatory authorities should therefore ensure compliance with good agricultural practices including withdrawal period of drugs used for treatment of food animals, while livestock producers should also be educated on responsible use of drugs in food animals. Routine drug residues surveillance and monitoring programs in meat and other edible livestock products should be established in the country to ensure food safety.