The Evaluation of Oxytetracycline Residues in Cow’s Milk in Tetovo, Macedonia

Oxiteraciclines are antibiotics widely used in the treatment of cattle against many infections caused by deferent gram-positive and gram-negative bacteria.This research was focused on qualitative and quantitative detection of oxytetracycline residues in cow’s milk produced in different rural areas of Tetovo in Macedonia. 138 milk samples were collected from 60 milking cows’ farms and are checked for oxytetracycline residues using qualitative ELISA test. From this control are found positive samples in 5, 8% (8/138) of milk samples. All positive samples are confirmed were by high-performance liquid chromatography (HPLC) method in Institute of Food Safety and Veterinary in Tirana. Analytical control carried out using HPLC resulted that only 6 /138 or 4.3% were positive for oxytetracycline residues. This evaluation of oxytetracycline residues with HPLC was carried out confirming following: 90ug/l, 180ug/l, 200ug/l, 4000 ug/l, 1600 ug/l and 1400ug/l (ppb) Al positive results are confirming treatment of milking cows with high doses of oxytetracycline so the level of oxytetracycline in the cow’s milk remain problematic. Keywords: oxytetracycline, cow, milk, Macedonia.