Distribution of Oxytetracycline residues in eggs from orally administered hens

Twenty five-week old hens (n = 6) were administered with an oral dose of 75 mg of Oxytetracycline (OTC) hydrochloride per day per head for five consecutive days and its residues in eggs as well as breast, leg and liver tissues were analysed by a high-performance liquid chromatography-ultraviolet visible detection (HPLC-UV) technique. The highest OTC residue concentration in egg white (0.5944 µg g−1) was significantly (p < 0.05) lower than that in yolk (0.6587 µg g−1), but the highest total OTC residue (18.8610 µg) as well as total OTC residue on any of the days from 2 to 10, in the entire white portion was significantly (p < 0.01) higher than that in entire yolk. Ratio of residue concentrations or total residue contents between white and yolk indicated partitioning of OTC residue in egg components. Mean cumulative residue and grand mean residue concentration were greater in egg white than those in yolk.

Keywords: hens eggs, meat, oral administration, oxytetracycline residue, OTC hydrochloride, egg white, egg yolk, antibiotics, public health, food safety, veterinary drug residues, muscle, liver tissues