Residues of tetracycline in imported frozen chickens in South West Nigeria

Imported old layer birds (100) sold for human consumption in open markets in Ogun, Lagos and Oyo States of Nigeria were analyzed for the presence of tetracycline using microbiological assay technique. The assay was done on antibiotic medium 2 agar seeded with Bacillus subtilis (NRRL-B-354). Results showed that 14% of the birds were positive for tetracycline residues deposition. The mean concentration of the residues was between 0.0316µg and 0.0513µg for thigh muscle samples while the concentration of the residues recorded from breast samples were between 0.0383µg and 0.0727µg. There was no significant difference (P>0.05) in the concentrations of tetracycline residues recorded in both muscle types. Location of purchase of the chickens also had no significant effect on residue deposition in the tissues. Keywords : residues, tetracycline, imported layers Tropical Veterinarian Vol. 23(1) 2005: 1-4