Phillip R. Myer is interested in ecological and metagenomic studies of microorganisms within the gastrointestinal tract (GIT) of beef cattle that are important to ruminant nutrition. He develops and applies molecular and microbiological tools to understand the biological mechanisms explaining differences in feed efficiency in beef cattle, the nutrition of grazing beef cattle, including forage intake, diet composition, nutrient requirements, supplementation, and interactions with the ruminal and lower GIT microbial communities, and the establishment of the rumen microbiome and its effects on growing beef cattle. Efforts to address these research interests include strategies focusing on the relationships among the microbial populations of the GIT and diet, management, and host genetics using physiological, molecular, and microbiological tools.