Some Factors Affecting the Growth and Development of Rats Fed Rancid Fat

Abstract

Rancid fat in the diet increases the protein requirement of the rat for optimum growth. A diet containing 10% rancid soybean oil (peroxide no. 530–550 µ moles/gm) supported almost normal growth in rats when all known essential nutrients were supplied in large amounts and protein constituted 30% of the diet. The difference in growth between a group of rats fed rancid fat with an optimum level of all other known nutrients and a group fed an equivalent fresh fat diet can be accounted for in the main by the lowered consumption of the rancid fat diets during the first days of the experimental period. The only organ weight seriously affected by the presence of the rancid fat was that of the intestinal tract. Whole desiccated liver, although it had effects on organ weights not attributable to its protein content alone, appeared to benefit the rats in proportion to the protein content when added to the diet. Cortisone had no beneficial effect on the growth of rats fed rancid fat under the experimental conditions employed. Several drugs administered to modify intestinal flora had no beneficial effects on the growth of rats fed rancid fat.