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Residual feed intake (RFI) is a moderately heritable trait that can be used to measure feed efficiency in beef cattle, and thereby reduce feed related costs. RFI has been primarily evaluated under drylot conditions where diet, feed intake and activity levels are controlled and foraging behavior is eliminated. Although previous studies have tried to measure RFI on monoculture pasture, it is difficult to accurately determine individual feed intake.�The objective of this study was to determine whether there is a difference in performance (weight gain, backfat recovery and methane production) between cattle with molecular breeding values (MBVs) for high and low RFI when foraging under open range conditions. This research was conducted at the University of Alberta Mattheis Ranch. A total of 450 commercial Hereford/Angus cows, with predicted MBVs for RFI, were separated into groups of high, low and medium efficiency. High RFI cows were bred to high RFI bulls, low RFI cows were bred to low RFI bulls and medium RFI cows were bred to medium RFI bulls, where the bulls had their own RFI phenotypes to produce groups of high, low and medium RFI calves. Production metrics, such as cow weight gain, backfat recovery, and breeding interval, along with calf growth, were collected for the 2015 grazing season. A subset of 60 replacement heifers, selected based on the MBVs of associated dams (30 high and 30 low RFI), were tested for actual feed intake and methane production using GrowSafe and GreenFeed technologies, respectively.�A smaller subset of 18 heifers were tested for methane production in June 2016 while grazing forage oat pasture using an open-path laser system. The presentation will further describe the results and show whether there is a significant difference in weight gain, backfat recovery and methane production between high and low RFI cattle.