Digestible Energy in Relation to Food Intake and Nitrogen Retention in the Weanling Rat

Abstract
It has been demonstrated that the food intake of two groups of weanling rats, whose rations contained respectively 20 and 30% of non-nutritive cellulose, was significantly influenced by the digestible energy content of the food. This would indicate that within physiological limits, as yet not determined, weanling rats eat to satisfy their energy requirements. Digestible energy consumption has been shown to influence the nitrogen retention of the weanling rat. Approximately 69% of the variation in the nitrogen retention of the weanling rats used in this experiment was associated with digestible energy consumption when the effects of initial weight were removed. It is postulated that within limits there is an optimum digestible energy level for each nitrogen level of a ration when the criterion of measurement is nitrogen retention.