The FDA drug-residue-sampling survey will involve 900 milk samples from dairy producers who have had a cull dairy cow residue violation in the past, as well as another 900 milk samples from randomly selected dairies.

The purpose of the sampling assignment is to see if there is a correlation between drug residues that may be showing up in the carcasses of cull cows with those that may be showing up in milk. Last September, at the 44th Annual Conference of the AABP, FDA official Dr. William Flynn said regulators want to know how cull-cow-tissue violators are doing in comparison to the industry as a whole. Flynn said the survey would be a “blind” study, meaning that regulators will not be able to tie a specific milk sample back to a specific farm.

The FDA will be using testing equipment and methodology that is far more sensitive than conventional screening tests. The FDA-CVM milk sampling assignment will screen milk from these dairies for 27 different drug residues using a multi-drug residue screening procedure validated by AOAC. The sampling survey is detailed in the FDA Laboratory Information Bulletin #4443.