The U.S. Food & Drug Administration announced March 5 results from its 2012 milk sampling survey, involving the testing of nearly 2,000 dairy farms for drug residues in milk.

According to FDA, more than 99% of the samples are free of drug residues of concern, which underscores the safety of the U.S. milk supply. These findings provide evidence that the nation's milk safety system is effective in helping to prevent drug residues of concern in milk, even in those limited instances when medications are needed to maintain the health of dairy cattle.

FDA explained that it 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. 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. However, the limited number of residues detected involved drugs that are not included in routine testing under the current milk safety program, FDA reported.

Despite the finding of a small number of drug residues in samples collected, FDA said it intends to take steps to maintain the strongest possible system to ensure milk safety. FDA will work closely with state regulators 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.

FDA said it is also working with its milk regulatory partners to update the existing milk safety program, as necessary, to include testing for a greater diversity of drugs and to educate dairy producers on best practices to avoid drug residues in both tissues and milk.

To read the full milk drug residue sampling survey report and to obtain additional related information, visit the FDA's webpage on drug residues.