Residual feed intake (RFI), an accurate predictor of feed efficiency, is difficult and expensive to measure. This disadvantage heightens the need for alternative cost effective measures for genetic improvement of feed efficiency in beef cattle. Recent Australian research has revealed that concentration of the protein hormone, IGF-1, in plasma is moderately heritable and is genetically correlated with RFI. The Australian genetic improvement system is now using genetic parameters to incorporate IGF-1 data into the computation of estimated breeding values (EBVs) for RFI. The IGF-1 measure is relatively inexpensive, but the EBVs for RFI generated from IGF-1 data alone have low accuracies (about 40%). The authors noted that to improve accuracy, strategies that combine measurement of IGF-1 in all breeding animals, and RFI measurement in strategically selected individuals in the herd in a two-stage selection process will be required (Herd et al. J. Anim. Sci. 82 [Suppl. 1]: 379).