Dr. Tim A. McAllister and his team have made a significant contribution to beef cattle microbiology, nutrition, food safety and sustainability in North America and beyond. He is one of few scientists to have published scientific manuscripts on all life forms, including livestock, plants, viruses, bacteria, protozoa, fungi and even prions. His work has spanned a range of scientific disciplines from applied on-farm studies to basic studies on genomics, microbiomes and mechanistic aspects of antibiotic resistance. He has authored over 900 peer-reviewed papers with a cumulative H index of 111. Dr. McAllister has been an engaged member of the American Society of Animal Science for over 20 years, serving as an Associate Editor and publishing 145 manuscripts in American Society of Animal Science journals. Many of the graduate students and postdoctoral fellows from his laboratory now hold faculty or research scientist positions in national and international universities, governments and industry.