Agriculture Secretary Tom Vilsack is being asked to explain comments he made earlier this month regarding his position on antibiotic use in food-producing animals.

Rep. Louise Slaughter (D-NY) and Sen. Dianne Feinstein (D-CA) sent a letter Sept. 15 to Vilsack seeking clarification of remarks he made at a National Cattlemen’s Beef Association meeting.

Responding to a question about legislation Slaughter and Feinstein have proposed, Vilsack reportedly said the use of antibiotics in livestock production can’t be banned. “USDA’s public position is, and always has been, that antibiotics need to be used judiciously, and we believe they already are,” he said as reported by Food Safety News.

The congresswomen explain that Vilsack’s comments represent a common claim that their legislation, Preservation of Antibiotics for Medical Treatment Act, introduced in 2009, would ban antibiotics used in agriculture. Instead, the bill would gradually phase out the use of seven antibiotics that are critical in human medicine.

USDA issued this response: “USDA believes that antibiotics should be used judiciously to slow the development of resistance in animals. USDA believes livestock producers are good stewards, use antibiotics judiciously, but there are some bad actors, and continued use can develop resistance. USDA wants to be a partner with Congress, producers and other federal partners to address this important issue.”