In some of the biggest news on the topic of routine antibiotic use in agriculture, Tyson Foods says today that they plan to eliminate most human-use antibiotics from their meat chicken flocks by 2017.

Tyson is the biggest chicken producer in the United States, so this announcement marks the largest commitment yet in poultry production. Taken together with the antibiotic-free purchasing commitment announced by McDonald’s earlier this year, this could be the  moment that transforms chicken raising in the U.S.

Some context: Small doses of antibiotics have been part of the diet of most meat animals since it was discovered in the 1950s that the drugs caused them to put on more muscle mass, allowing them to get to market weight faster or with less feed, and also