More than half of the chicken sold by Perdue can be labeled “no antibiotics ever,” a first for a major poultry company.

It took Perdue roughly a decade to achieve that goal by perfecting the commercial raising of chickens without antibiotics of any kind, The New York Times reports.

Competitors like Tyson and Foster Farms making similar moves, as customers like McDonald’s and Chick-fil-A demand it. But those companies continue to to use ionophores — antibiotics not used in human medicine.

Perdue is making that point clear in new ads featuring Jim Perdue, the chief executive and the grandson of Perdue’s founder.

“Some of my competitors plan to reduce their use of antibiotics over the next few years — but what are you having for dinner tonight?” Perdue asks in one ad promising “no antibiotics ever” chicken.