The nutritive value of some cotton-seed products in growth

Abstract

When certain animals are fed on a ration containing an abundance of cotton-seed meal they frequently give evidence of so-called cotton-seed injury. This has been attributed to irritation from the indigestible husks, the oil, harmful microorganisms, and specifically toxic chemical compounds. The possibility suggests itself that the rations are frequently far from ideal or adequate in respect to the various essential nutrients, inorganic salts and “accessories.” Richardson and Green 1 have found that when the ration of rats is otherwise suitable, toxic symptoms do not follow the use of cotton-seed meal. With their approval we refer to our own experiments, which are still in progress. To ascertain whether the cotton-seed proteins are notably deficient for the purposes of nutrition, we have conducted feeding experiments on rats in which these proteins furnished practically all of the food nitrogen and in which the other essential dietary components were supplied by adding to the products to be tested a suitable mixture of “protein-free milk,” butter fat and starch which, with the addition of adequate protein, has been shown in hundreds of experiments to be sufficient for perfect growth. In this way we have found that satisfactory growth can be made by rats when either cotton-seed globulin or the total cotton-seed protein precipitated from alkali extracts of cotton-seed meal is employed without other significant protein sources in the mixture. No toxic symptoms have appeared, even when the supposedly harmful meal also was used, during a period in which the animals reached a large size. In experiments in which the inorganic components were furnished by our “artificial protein-free milk” there was no failure of growth when the cotton-seed meal was used, thus suggesting that the latter contains the equivalent of the “determinant,” “food accessory,” or “vitamin” deemed essential for nutrition and furnished in fat-free milk.