Sigestible energy (DE), metabolizable energy based on a regression equation, the ME values (ME) and metabolizable energy corrected i6 for swine feeds can be ietermined most effeclitroge,n e-quilibrium (ME") wiie determined tively by multiplying DE X 0.98). This pro. for eight.feeds. Efiects of protein level in the videi a hetaboiiiable energy value applicible basal ration and of level-of feeding certain within the protein levels-used in plactical test feeds were also studied. Protein level of swine produition. ME values thus-derived the test ration was found to be inversely cor-were: soybean meal 3620, rapeseed meal related with the ratio ME/DE 1r ---O.9SO; 328O, heriing fishmeal 4550,-wheit 3965, bar-4 < 0.01)' It was postulated that conven-ley 3175, oats 2900 and wheat shorts 3040 tional methods for estimating ME and ME" kial/kg dry matter.underestimate high protein feeds and that,