Oxytetracycline Residues and Their Antibacterial Activity in Eggs Laid by Hens Administered by Therapeutic Dose of Oxytetracycline via Drinking Water

Abstract

Eggs laid by laying hens administered oxytetracycline via drinking water with dose 2 g/l for 7 consecutive days were evaluated their oxytetracycline residues and antibacterial activity on the 2nd, 4th , 6th day of administering and the 2nd , 7th , 14th day of stopping. The results indicated that oxytetracycline residues and their antibacterial activity had been found in egg shells and eggs, white since 2nd day of administering, whereas in yolks since the 4th day. The residues were still found both in eggs, white and yolks at concentration of 0.01 ppm on the 7th day of stopping oxytetracycline administration. The oxytetracycline residues concentration of 0.01 ppm were under permitted maximum residue limit, however there still showed antibacterial activity in eggs white, while there were no antibacterial activity in yolks. Eggs had been free from oxytetracycline residues and their antibacterial activity on the 14th day of stopping oxytetracycline administration to hens. Keywords : oxytetracycline, hen, egg, residue, antibacterial activity