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These projects were conducted in the subhumid rangelands (Klemme Research Range [K LEMME ]) and on introduced forages Oklahoma (Eastern Research Station [ERS]) USA. Targeted supplementation to increase performance of growing cattle, maximise production per hectare, and replace synthetic fertiliser on pasture. Treatments at Klemme included: 1) Positive Control (PC) – 1 kg daily supplementation with distiller's grains (DDGS) cubes in late summer, or 2) High Supplement (HS)-DDGS cubes offered at 0.75% of liveweight all summer with 33% increase stocking rate. Treatments at ERS included: 1) Fertilized Control (FC)-no supplementation on N fertilized pastures; 2) Fertilized Supplement (FS) – steers fed 1.2 kg/day supplemental DDG cubes on N fertilized pastures throughout the summer; or 3) High Supplement (HS) – steers supplemented DDG cubes at 0.75% of BW/d on unfertilized pastures.. The HS treatment increased LW gain/ha by 89% compared with PC at KLEMME and increased steer performance while replacing synthetic N inputs in FC and FS treatments at ERS. At KLEMME, calculated N use efficiency, N2O emissions, methane emissions, total CO2 equivalent emissions and CO2 equivalent emission intensity (kg /kg LWG) were decreased in HS. At ERS calculated N use efficiency, N2O emissions, total methane emissions total CO2 equivalent emissions and CO2 emission intensity were intermediate for HS, but CO2 equivalent emission intensity was improved. Performance of steers followed through finishing on high-concentrate diets were not affected by previous supplementation treatment during grazing and increased gains prefinishing resulted in similar carcass weights with decreased days on feed and 15% less total feed required for finishing without impacting carcass quality. Targeted supplementation has the potential to increase performance in intensified grazing systems, increase beef production per hectare, and reduce grazed forage and harvested feeds with the potential to reduce the over all environmental impact of beef production.