Estimating feed efficiency and emissions of mature beef cows on pasture faces technical
challenges, with little information on the consistency of enteric emissions between the dry lot
and pasture. This research examined relationships between feed efficiency, enteric methane
(CH4), and carbon dioxide (CO2) of beef cows in the dry lot and pasture. The trial first monitored
feed intake, CH4 and CO2 production, weight, and backfat depth every 28 days for 10 weeks in
64 pregnant multiparous beef cows in the dry lot. Post-calving, cows were randomly assigned to