Farm Test for Rapid Identification of Antibiotic Residues in Raw Milk

Bovine mastitis is the most frequent disease in dairy cattle, which requires the use of antibiotics to control and prevent new infections.However antibiotic drug use in food-producing animals may leave potentially toxic waste, especially when improperly administered.Thus, continuous monitoring of the maximum level of antimicrobial residues in milk is important to avoid risks to human health and interference in the industrial process of dairy products.In this work we compared the efficacy of two on-farm screening tests, SNAP duo beta-tetra ST test and Eco test BT, for the qualitative detection of beta-lactam and tetracycline residues in milk.We analyzed 254 milk samples from Rio de Janeiro state in Brazil, one of the largest milk producers, and our data showed negative results for the animals not treated for bovine mastitis.However, the animals treated with ampicillin and cloxacillin was positive for beta-lactam residues in all samples tested, in both kits.Eco test BT showed false positive results for betalactam residues in mixed milk samples from two untreated animals in two different herds.This may be due to the presence of antibiotics, but also other substances that may interfere with the test (eg.bacteria or somatic cells).Our results confirmed that the SNAP duo beta-tetra ST test could be a useful tool for detecting antimicrobial residues in milk on farm.Eco test BT that should be analyzed in the future.