The Contamination of Antibiotics Residues and Microorganisms in Raw Cattle Milk Collected from Cha-Am District, Phetchaburi Province, Thailand

Introduction: Antibiotics were used widely for treatment of bovine mastitis in Thailand. The improper use of antibiotics in dairy cattle farms may lead to antibiotic residue contamination in milk. Antibiotic residues can have adverse effects on some allergic individuals. Therefore, milk quality can be determined by the occurrence of antibiotic residues. Moreover, one of the requirements in the production of high quality raw milk is maintaining acceptable bacterial counts which meet the official milk quality standards.

Purpose: This study aimed to monitor antibiotic residues and microbiological quality of individual raw milk samples from dairy cattle farms in Cha-Am district, Phetchaburi province, Thailand.

Methods: Ten individual raw milk samples from six dairy cattle farms were randomly collected every month from September 2011 to January 2012. In total, 300 raw milk samples were tested. Antibiotics residues were tested using 3M Antibiotics Detection Kit for detection of Beta-lactams, Quinolones, Sulfonamides and Tetracyclines. The contamination of aerobic bacteria, Coliforms and E. coli were determined by 3M Petrifilm Aerobic Count Plate and 3M Petrifilm Escherichia coli/Coliform Count Plate, respectively.

Results: Percentages of antibiotic residues that were found in each farm over the five-month test period ranged from 0% to 14% for Beta-lactams, 2% to 6% for Quinolones, 0% to 14% for Sulfonamides and 0% to 12% for Tetracyclines. More than 80% of samples from each farm collected over the five-month period had aerobic plate counts < 200,000 CFU/ml. In 90% of raw milk samples, contamination of E. coli and Coliforms were < 10,000 CFU/ml. 

Significance: Antibiotic residues were detected in raw cattle milk in Thailand. Therefore, farmers should be educated about how to use antibiotics properly for preventing disease in their farms.