April 18th 2013
FDA’s Milk Drug Residue Testing Assignment
Questions & Answers
Q: I’ve heard that FDA has been testing bulk tank milk for drug residues. What’s going on?
A: The Food and Drug Administration (FDA) sometimes initiates a sampling project in order to determine if a potential food safety issue requires additional regulatory attention. Within the next one to two months FDA expects to release data from a year-longsampling assignment where bulk tank milk from dairies with a history of carcasstissue residues was compared with bulk milk from dairies without such a history.
Q: Why did FDA do this? What do tissue residues have to do with milk?
A: The US Department of Agriculture has identified a small number of farms that have repeatedly marketed cows and/or calves that were later found to contain drug residues.The FDA intends to ensure that milk from these farms does not also contain drug residues.
Q: Don’t we already test all milk tankers for drugs at the processing plant?
A: Yes. Every tanker in the U.S. is tested for the penicillin family of treatments, the most important family of drugs relative to reactions in humans. The sampling assignment in this current project also included the sulfa, tetracycline and gentamicin families of antibiotics, as well as some anti-inflammatory drugs such as flunixin.
Q: How did FDA determine which farms to sample?
A: The samples were taken from farms across the United States.FDA sampled bulk tanks from 1,800 dairy farms. Half of the farms (900 facilities) had experienced at least two drug residue detectionsin slaughter animalswithin the last three years. Sampling priority was based on the frequency, magnitude and type of tissue residue violations. The remaining 900 farms (farms not having a similar residue history) were selected at random to serve as the experimental “control”.
Q: What did the FDA find during the project?
A: The data has not been released.
Q: Is the milk supply in the U.S. safe?
A: Yes. The FDA has repeatedly affirmed its confidence in the safety of the nation’s milk supply. Due to existing safeguards, reports of even mild adverse reactions to drug residues in milk are virtually unheard of in modern medical literature. FDA believes that these expanded sampling efforts will ensure that any problem that may exist will be detected and eliminated quickly by education and enforcement.
Q: What will happen to those farms whose bulk tanks contained residues?
A: Because typical processing and mixing proceduresare expected to reduce residue levels to well below those of human health concern, the FDA determined that recalls would not be required as part of the study. As part of the experimental protocol all samples were blinded and could not be traced back to a particular processor or farm.
Q: What will the FDA do as the result of the project findings?
A: Options to strengthen the already highly effective existing milk quality safeguards are under discussion by regulatory agencies and industry, but will dependent on the project results. Actions that might be taken in the future could include some combination of education, increased testing and enforcement.
Q: Are there residue prevention training materials I can use for employees?
A: An excellent training video on preventing drug and toxin residues in meat and milk is available for free download at UC Cooperative Extension’s “Dairy Beef: Maximizing Quality & Profits” website In addition, the national Dairy FARM program has a residue prevention primer available at . The California Dairy Quality Assurance Program provides additional information on their website at
Q: Is there any way to test my cows for residues before marketing them?
A: The only validatedpre-slaughter on-farm test currently marketed is the “Meatsafe” assay for cow urine. This test will pick up the penicillin class of drugs including amoxicillin, ampicillin, cloxacillin, hetacillin and penicillin G. It will not pick up the cephalosporin drugs (cephapirin, and ceftiofur), or the tetracycline, sulfa or gentamicin families. It also will not detect the anti-inflammatory drug flunixin.
Q: Who should my processor or trade organization call if they are interested getting more information?
A: The California Dairy Quality Assurance Program works with producers and processors to provide accurate and useful information related to environmental stewardship, animal care, food safety and farm security. Trade organizations or processors interested in additional educational materials or scheduling group workshops should contact Dr. Michael Payne at or 530-304-9306.
California Dairy Quality Assurance Program
502 Mace Blvd., Suite 12, Davis, CA 95616
Toll-free (866)66-CDQAP (866)662-3727 fax (916) 441-4132