Alcohol-extracted beef liver was fed to albino rats as the only source of protein in a ration adequate in the recognized factors necessary for normal nutrition, the vitamins being supplied by yeast, cod liver oil and hydrogenated cottonseed oil (Crisco) ; the latter furnished the fat of the basal diet. The ration was found to be inadequate for optimum growth, reproduction and lactation. Supplementing the basal diet with 0.5 g. of raw liver or replacing the extracted-liver of the basal diet with whole dried liver greatly increased the growth rate and improved lactation