The Food and Drug Administration reports that the number of antibiotic-positive milk tankers was just 0.026% for the fiscal year ending September 30, 2009. That's a decrease of 7% from the previous year. The full report can be found here
"Stronger on-farm animal care programs and intense testing at the dairy plant are continuing to show impressive decreases in the FDA-sponsored National Milk Drug Residue Dtabase testing results for medicinal animal drug residues," said Allen Sayler, IDFA Vice President of Regulatory Affairs. "The program of testing every truckload of raw milk and disposing of those testing positive is very successful in maintaining confidence in dairy products and in the dairy industry."
More than 3.9 million samples were tested. In addition, more than 45,000 samples of finished dairy products were also tested, and none of these was positive.
The amount of milk that had to be disposed of because of "hot” loads in fiscal year 2009 decreased 13% from 2008, and 58% from 2007.
The data was also sorted between Grade A bulk milk tankers and non-grade A tankers. The Grade A tankers were positive 0.025% of the time; the non-Grade A tankers were positive 0.037%. Note that Grade A milk makes up approximately 95% of the U.S. milk supply.
Beta-lactam drugs were the primary drugs of interest, accounting for 98% of all tests conducted. But FDA also increased its scrutiny of enroflaxin and sulfonamide drug families, and is currently assessing
if more classes of drugs should be added to the testing regime.