Evidence for an Unidentified Growth Factor(s) from Alfalfa and Other Plant Sources for Young Guinea Pigs

An improved purified diet for the guinea pig has been described which is suitable for assay of a proposed unidentified growth factor(s) found in alfalfa and other plant sources (such as soybean meal, dried broccoli, and dried broccoli, and dried grass clippings). Improvement in growth of up to 50 g over a 3-week assay period was obtained by adding 10% of dehydrated alfalfa to the diet. The factor(s) appears to be distinct from all known vitamins, minerals, amino acids, or other nutrients. It appears to be organic in nature, since it is not found in the ash of alfalfa. The relationship of this “plant factor” to the “grass juice factor” or to other reported unidentified factors for other animals is unknown at this stage. Attempts to identify the factor(s) are in progress.