The nation's food safety system is effective in preventing drug residues of concern in milk, the U.S. Food and Drug Administration said Thursday, as evidenced by results from its milk sample testing of nearly 2,000 dairy farms.
In its tests, the FDA found that more than 99% of milk samples were free of drug residues of concern. Samples were tested for antibiotics, non-steroidal anti-inflammatory drugs, and an antihistamine.
The agency initiated the study to determine whether dairy farms with previous drug residue violations in tissue derived from dairy cows were more likely to have violative drug residues in milk than other dairy farms.
The FDA tested samples from two groups: a "targeted" list of farms with known previous tissue residue violations and a control group of farms. Results show that the occurrence of drug residues in milk is very low, even in the targeted group, FDA said. However, the limited number of residues detected involved drugs that are not included in routine testing under the current milk safety program.
Despite the finding of a small number of drug residues in samples collected, the FDA said it intends to take steps to maintain the strongest possible system to ensure milk safety.
FDA plans to consider modifying testing to include collecting samples as necessary from milk tanks on farms when investigating illegal drug residues in tissues involving culled dairy cows; and working with its milk regulatory partners to update the existing milk safety program, as necessary, to include testing for a greater diversity of drugs.
FDA said it also plans to educate dairy producers on best practices to avoid drug residues in both tissues and milk.
The FDA establishes a Pasteurized Milk Ordinance that provides a model for states to adopt to ensure milk safety.
Under the PMO, milk samples are collected every time raw milk is picked up on a farm. A milk sample is also taken when a truckload or bulk tank of milk arrives at a Grade "A" dairy plant for processing.
Each arriving truckload of milk at the plant must be tested for the presence of at least four of six specific Beta-lactam drugs (penicillin, ampicillin, amoxicillin, cloxacillin, cephapirin, and ceftiofur). If this bulk milk sample shows concerning results, each farm that supplied milk for that truckload will undergo mandatory testing.
This most recent survey of nearly 2,000 farms, however, was a surveillance-oriented sampling survey that looked for drug residues that are not currently included in testing under the Grade “A” milk program, FDA said.