Nutritive value of meat meals. I—Possible growth depressant factors

When fed as supplements in a well‐balanced diet for the rat, a commercial meat‐meal sample and various heat‐damaged laboratory preparations including pure tendon stimulated growth, thus providing contradictory evidence to previous reports of possible toxicity in such materials. An increase in dietary ash level, similar to that brought about by addition of meat meal, caused no growth depression in rats given, as their sole source of protein, gut preparations low in ash. Freeze‐dried tendon had as low a value as oven‐dried tendon in sole protein experiments in which rats lost weight and died. Meat meal itself supported slow growth and no further response was obtained with supplements of methionine, cystine, tryptophan and lysine.