Currently raw milk leaving U.S. dairy farms and destined for human consumption is tested for the beta lactams (penicillin) class of antibiotics. The U.S. Food and Drug Administration met with opposition from milk producers and dairy industry executives when it announced plans to begin testing milk for other drugs, as a result of an increased number of drug residues found in the meat of certain dairy cattle sold for slaughter. Mike Hutjens, a recently retired dairy specialist with University of Illinois Extension, spoke with News Bureau reporter Sharita Forrest about the controversy.
What is the current testing process for milk?
A sample of milk is taken from every dairy farm when it's picked up, and that sample is tested for the presence of beta lactam antibiotics. If that sample is discovered to have drug residue, then the milk is discarded, the farmer is notified and cannot sell any more milk until the bulk tank tests negative for antibiotics. Then he has to go through a drug-residue certification program with his veterinarian and his milk-processing company. If drug residue is found a second time, the farmer is fined. If it happens a third time in a 12-month period - and I'm not aware of this ever happening in Illinois - the farm loses its milk production permit and can't sell milk.
In Illinois, the Illinois Department of Public Health, Dairy Division, issues permits to sell milk and also inspects the facility to make sure it meets the requirements.
The program that the FDA is proposing significantly expands the number of drugs that would be tested for, from six to about two dozen. Why such a large jump?
Only certain antibiotics are cleared for use with lactating cows, and that's what they're currently testing for in milk. There are many other classes of drugs potentially used on farms that are not routinely tested for in milk, such as sulfonamide antibiotics and anti-inflammatories, such as flunixin. But beef can come from veal calves, steers or culled cows, and these animals could be treated with other drugs that are not cleared for use in milk cows. The new testing program was proposed to determine if there are other classes of drugs that may be found in milk, and targets dairy farms that have been egregious tissue-residue violators.
The residue levels found in all beef is nearly zero, but when the FDA does find a beef drug residue, it is usually found in a cull dairy animal.
How concerned should we be about drug contamination of the milk we buy at the grocery store?
In terms of milk quality and drug residue, the U.S.'s track record can't get much better than what it is. In 2010, the U.S. had more than 53,000 dairy farms, which milked more than 9.1 million cows, producing 192.8 billion pounds of milk. The level of drug residue detected last year was .02 percent - two hundredths of 1 percent.
How are drugs ending up in milk? And what precautions are taken to keep them out?
When a cow is treated with antibiotics for mastitis, an inflammation of the mammary gland, or some other infection, the cow is marked with a band or some identification so that its milk won't be mixed with the rest of the milk from that herd.
Farmers will isolate cows that are treated with antibiotics in a hospital pen, and their milk will be discarded or fed to calves. But sometimes cows will escape from the pen and mix with the herd or they'll lose their bands and get milked along with the rest.
These kinds of accidents are rare, but they do happen. That is why all raw milk is tested for the most common antibiotics, the beta lactams class, before it is processed at a milk plant.
Antibiotics were banned from use in dairy cow feeds many years ago, although there are products that can still be fed to calves or beef steers. If that feed is mixed in with the dairy cow ration inadvertently, the drug residue could enter the milk supply that way.
Why are dairy farmers and industry officials opposed to the FDA's proposed testing program?
The dairy industry and farmers are opposed to the FDA's proposed process, which would require farms to retain milk from seven to 12 days, depending on the number of retests required to clear it for sale. The Pasteurized Milk Ordinance requires that milk be processed within 72 hours of harvest. So, either the milk would have to discarded until proven clean or the milk could be cleared by the current testing program only to find out seven to 12 days later that residue was found. Who would absorb the loss?
Then there would have to be a national recall of any dairy products made from contaminated milk.
Milk is probably the most highly tested food product, and no dairy products have ever been pulled because of drug residues.
I think another concern is that people will assume that the testing is being done because there is a residue problem, and this could possibly damage the market.
What's the current status of the FDA's proposed testing program?
The FDA is getting more input from the state regulatory agencies and from the milk-processing companies. According to the latest information from the National Milk Producers Federation, it appears that the FDA has decided to proceed with a screening program but will use blind sampling to minimize marketplace disruption.