Antimicrobial resistance is an increasingly serious threat for public health, and the use of antimicrobials in livestock feed has been a major contributing factor in the emergence and spread of antimicrobial resistance to many drugs, according to the U.S. National Institutes of Health. The poultry industry is evolving toward antibiotic-free production to meet market demands and decelerate the spread, and Penn State researchers are helping to identify and better understand alternative approaches.