The potential of high protein OP cultivars to donate this trait was investigated by crossing five OP cultivars with six inbred testers. The topcrosses, OP parents and five hybrid checks were evaluated for yield, % lodging and % grain crude protein with two replicates per field and three fields per year in 2003 and 2004. There were significant differences among the OP donors per se and in crosses. A predicted three-way cross analysis showed one hybrid (NY73118/CO388) could have its crude protein raised through crosses with two cultivars from the Northern Flint race. A second experiment was carried out by crossing 28 S0 plants of one flint cultivar with two single-cross testers. These testcrosses were evaluated with two replicates in two fields in 2003 and 2004. Two plants had the potential to raise the crude protein of the testers without substantial yield drag. The value of the increase in grain protein was modelled using a spreadsheet tool (CornPro3) and the CPM Dairy Ration Analyzer. Using 2004 Iowa costs of production and average yields, small cost savings (<5%) appeared plausible if higher protein maize was used in rations of steers, dairy cows and pigs. Using spring 2005 prices and average rations for dairy cows in New York, very small cost savings, minor reductions in manure P and minor increases in manure N were predicted. Higher protein maize was predicted to slightly improve milk production in average cows and to slightly reduce it in high-producing cows. Higher protein maize appears unlikely to greatly benefit farmers or to reduce potential nutrient importation or losses via manure. Its potential for retaining more N during the growing season has yet to be assessed with high protein-high yield cultivars.