Assessment of Antibiotic Residues in Raw and Pasteurized Milk Produced by Different Analytical Methods

Background: Due to lack of attention to the required time of emulating the absorbed doses of drugs from different organs, inappropriate use of antibiotics for disease treatment in animals causes many adverse health effects in consumers. In this study, the antibiotic residues in raw and pasteurized milk were evaluated in Neyshabour city. Methods: Raw and pasteurized milk samples were collected from eight farms and milk collection units and four pasteurized milk production factories in Neyshabour city during the warm and cold seasons. 56 samples of raw milk and 24 samples of pasteurized milk were analyzed using the Copan milk test, Tri-Sensor kit and ELISA detection methods to evaluate presence of the antibiotic residue. Results: Copan milk test and Tri-Sensor kit did not detect the antibiotic residue. ELISA kit was able to detect the presence of gentamicin and streptomycin in milk. 25% of the samples contained gentamicin, while 10% of the samples contained streptomycin. The amount of antibiotic residue in the warm season was higher than cold season. 58.3% of pasteurized milk samples in the warm season had gentamicin. Conclusion: Based on our results, extensive and accurate monitoring of antibiotics in raw and pasteurized milk needs to be performed in the city, especially in warm seasons.