A stunning 70 percent of all antibiotics important in human medicine in the U.S. are sold for use in animal agriculture. These lifesaving drugs are fed routinely to animals that are not sick in order to promote growth and prevent diseases that spread easily in crowded, filthy factory farm conditions. Public health agencies have declared antibiotic resistance a top health threat in the U.S. -- and the rampant misuse of antibiotics in livestock production is a major cause. Chain Reaction II is the second annual report and scorecard that grades America’s top restaurant chains’ on their policies and practices regarding antibiotics use and transparency in their meat and poultry supply chains. The good news is that consumer and investor pressure has pushed twice as many companies as last year to create more responsible antibiotics policies, particularly for chicken. The bad news is that Olive Garden, KFC and 14 other chains received F grades and little progress has been made on pork and beef. Only two restaurant chains received an A grade: Chipotle and Panera. Read the 2016 scorecard to see how restaurants fared.