© Reuters. FILE PHOTO: The logo of Tyson Foods is seen in Davos, Switzerland, May 22, 2022. REUTERS/Arnd Wiegmann/File Photo

(Reuters) -Tyson Foods is reintroducing certain antibiotics to its chicken supply chain and will drop its “no antibiotics ever” tagline from Tyson-branded chicken products, a Tyson spokesperson said on Sunday.

This will involve drugs that the company said are not important to human health.

The antibiotics that Tyson plans to add to some of its chickens’ diets are known as ionophores, a Wall Street Journal report said on Sunday, citing people familiar with the matter. This will affect all fresh, frozen and ready-made products under its brand.

Ionophores are mainly used to control a disease in poultry called coccidiosis, maintain intestinal integrity, and help deliver good bird health. According to the report, the World Health Organization does not consider them to be medically important for treating human illnesses.

“Based on current science, Tyson branded products are transitioning to No Antibiotics Important to Human Medicine (NAIHM) which is expected to be complete by the end of the calendar year,” a Tyson Foods (NYSE:) spokesperson said.

In 2017, the U.S. meatpacker had switched its retail line of company-branded chicken products to birds raised without any antibiotics.