Oxitetracycline residue in cow milk after intrauterine application

The paper examines the excretion of oxitetracycline residue in milk of East Friesian cows that received a single intrauterine treatment. A total of 10 cows were divided into two equal experimental groups, and one group was administered a dose of 0.5 g/cow, and the other group 1 g/cow oxitetracycline. Oxitetracycline residue in milk was determined using the Rezazurin test method with Str. Thermophilus, as the test microorganism. Following the i.u. administration of oxitetracycline in a dose of 0.5 g/cow the average duration of the presence of its residue in milk in treated cows was 46.0 (34-58) hours, with oxitetracycline residue concentration ranging from 0.1-1.4 mcg/ml milk. After the dose of 1 g/cow, this time period was 55.6 (34-82) hours, and the oxitetracycline residue concentration ranged from 0.1-2.2 mcg/ml milk