Iron Deficiency Studies in Chicks Using Treated Isolated Soybean Protein Diets

Abstract

In experiments on freeing isolated soybean protein of its mineral elements, the levels of zinc, molybdenum, manganese, calcium and magnesium were reduced approximately 35, 40, 75, 85 and 95%, respectively, by washing the protein with water. When the protein was treated with the disodium salt of ethylenediaminetetracetic acid (Na₂EDTA) or the pentasodium diethylenetriaminepentoacetic acid (Na₅ETPA), the levels of these mineral elements were decreased 100, 70, 80, 85 and 95%, respectively. Copper and iron were not reduced by the water treatment, but were lowered approximately 65 and 50%, respectively, by the Na₂EDTA treatment. In studies with chicks, fed diets containing Na₂EDTA-treated isolated soybean protein, together with graded amounts of iron, the iron from the untreated soybean protein was found to be available for growth, hemoglobin formation and cell volume. On the other hand, iron which was added to the treated soybean protein basal diet was not as available for growth, hemoglobin formation or cell volume as the iron from the untreated soybean protein basal diet. The iron remaining in the protein after the Na₂EDTA treatment and the graded levels of iron added to the treated soybean protein basal diet were less available for growth, hemoglobin and cell volume, when Na₂EDTA was added to the diet than when the diet contained no added Na₂EDTA. Iron deficiency caused depigmentation of the feathers of New Hampshire chicks which was not related to the copper level of the diet. The results of the investigation showed that, under some conditions, the iron requirement of the chick is greater than that previously reported.