Subway announced Tuesday that it will be switching to antibiotic-free meats. The sandwich chain made the decision after advocacy groups called for the switch, reported ABC News.

Subway is going one step farther than some of its competitors who only promised to transition to antibiotic-free poultry. The sandwich company provided a timetable for the the transition not only for chicken, but also for turkey, pork and beef.

The company said it will start serving antibiotic-free chicken beginning in March 2016. Within two to three years, the transition to antibiotic-free turkey is expected to be complete, and in 2025, the company plans to complete its transition to antibiotic-free pork and beef.

"A change like this will take some time, particularly since the supply of beef raised without antibiotics in the U.S. is extremely limited and cattle take significantly longer to raise. But we are working diligently with our suppliers to make it happen," said Dennis Clabby, executive vice president of Subway's Independent Purchasing Cooperative, in a news release.

Giving antibiotics to poultry, hogs and cattle has long been a practice in the livestock industry. However, this has become a major public health threat because bacteria in meat can develop resistance against antibiotics, giving rise to superbugs. People who become ill from eating meat infected with antibiotic-resistant superbugs no longer respond to treatment.

Last week, a coalition of advocacy groups informed Subway that they will deliver petitions to the restaurant's headquarters in Connecticut Thursday, signed by more than 300,000 people, calling for the sandwich chain to stop using meat from animals that are given antibiotics. Subway's announcement came ahead of the scheduled petition delivery, reported Reuters.

The sandwich chain said its decision to transition to antibiotic-free meat was the "culmination of several months of intensive work with suppliers" and not a response to any petition.

"Today's consumer is ever more mindful of what they are eating, and we've been making changes to address what they are looking for," said Clabby.