Growth and Reproduction on Synthetic Diets. II

Abstract

Three generations of rats have been reared on a synthetic diet of butter (12 gm.), caseinogen (20 gm.), potato starch (64 gm.), salt mixture of Hartwell (4 gm.), Marmite (5 gm.), and distilled water (300 cc). Good growth and reproduction were obtained, but the rearing of young was not up to standard. The use of cod-liver oil in place of butter produced less good growth and caused sterility, probably due to vitamin E deficiency. Synthetic diets are described which produce good growth in young rats, but cause failure of the young to be born and consequent death of the female. Further evidence is given that the dietary requirements of the rat vary at different phases of its existence.