Thesis (M.S., Animal and Veterinary Science)--University of Idaho, June 2014 | Feed is the largest variable cost associated with beef production, any reductions of feed inputs whilst maintaining outputs will result in direct increased profitability for the industry. Traditionally individual feed intake has been expensive and laborious to measure. Recent improvements in technologies for measuring individual feed intake have made incorporating the phenotype into breeding selection decisions possible. Residual feed intake (RFI) is defined as the amount of feed that an animal consumed adjusted for the expected consumption based upon requirements for maintenance and growth. RFI is independent of body weight (BW), gain (ADG), carcass and meat quality. RFI is highly correlated with feed intake (DMI) and moderately heritable (r = 0.40). There are differences in feeding behaviors amongst the divergent RFI classes, animals with low RFI tend to spend less time eating per day and have fewer overall meals per day. There are many documented differences between low and high RFI animals, by adding to the knowledge base on RFI there should be increased producer and industry adoption.