Milk production in developing and tropical countries is subject to different constraints than in the US. Even large, advanced dairies in Malawi have different inputs of energy and materials to optimize their milk output compared with moderate sized dairy farms in the US The objective of this study was to compare energetic inputs, outputs, and efficiencies of dairy farms in Malawi (southeast Africa) and North Carolina to assess sustainable milk production. Feed consumption and milk production data were collected from Katete Dairy herd in Lilongwe, Malawi, consisting of 408 cattle with 108 lactating cows, and the NCSU Dairy Research and Teaching Farm, housing 245 Holstein and 55 Jersey cows and 170 lactating cows. Both are teaching farms that employ extensive record keeping. Milk production averaged 34 and 19.5 kg/cow/day at NCSU and Katete, respectively. Feed energy intake was 85.8 Mcal/cow/d at NCSU and 135 Mcal/cow/d at Katete. Thus, return of feed energy as milk energy was 24.7% efficient at NCSU and 11.3% efficient in the lower producing cows at Katete. Manure is recycled for crop production at Katete, and is processed with a solids separation and lagoon system at NCSU. Additional factors that impact the overall farm efficiencies include inputs of petroleum fuels and electricity, and the number of calves, heifers and dry cows fed. The project identifies factors in dairy production that should be considered to improve efficiency, sustainability, and milk supply. Both farms had a substantial portion of the energy fed to the cows lost to the environment as composted manure in soils or lagoons that did not capture the heat or methane generated.