Antibiotic residues in milk reached their lowest level in 24 years, with just 0.009% of tankers testing positive in the fiscal year ending September 30, 2019. So reports the National Milk Drug Residue Database (NMDRD).
In 1996, the residue rate was 0.104%. With education and more enforcement, the rate has been dropping steadily ever since.
Of the nearly 3.6 million Grade a tanker loads of milk tested in fiscal year 2019, just 327 of these were reported positive. These positive loads, representing 14.7 million pounds of milk, were disposed of and did not enter the food supply.
Residues in producer milk, sampled directly from farm bulk tanks, was higher, however. Of the 333,000 Grade A bulk tanks sampled in 2019, 223 tested positive. That’s a positive rate of 0.067%.
Grade B tankers and bulk tanks had slightly higher rates of positive tests. The Grade B tankers had a positive rate of 0.012% and Grade B bulk tanks had a positive rate of 0.095%.
The NMDRD reports 3,997,738 samples were collected, and some of these samples were tested more than once. Of the total 4,128,838 tests run, 567 tested positive. All of those testing positive were for beta lactams. Nine of the positive samples also tested positive for sulfonamides (5) and tetracycline (4). None tested positive for sulfamethazine.
You can view all of the results here.