Dr. Robert J. Collier is among the few animal scientists who has impacted development of animal agriculture world-wide. He attended Eastern Illinois University (BS, MS), University Illinois (PhD) and Michigan State University (NIH Post-Doc) and has been employed by US Army (Medical Technician), Monsanto (Director of Research) and Universities of Florida and Arizona (Faculty). Collier’s research addressed two of the pressing problems of human society – the increased demands for food production caused by increases in global population and the problems in meeting that demand caused by global climate change. Collier and coworkers characterized the cellular and molecular changes in the mammary gland and the alterations in metabolic endocrinology caused by heat stress, devised innovative systems to estimate the magnitude of heat stress effect on cattle, and identified management systems and feeding strategies to reduce or mitigate the impact of heat stress.