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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Research » Publications at this Location » Publication #97824
Title: PHYTASE IMPROVES IRON BIOAVAILABILITY FOR HEMOGLOBIN SYNTHESIS IN YOUNG PIGS

Author
item STAHL, C - CORNELL UNIVERSITY
item HAN, Y - CORNELL UNIVERSITY
item RONEKER, K - CORNELL UNIVERSITY
item House, William
item LEI, X - CORNELL UNIVERSITY

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Iron deficiency anemia is a common debilitating disorder in children and premenopausal women. This nutritional disorder may result from excessive consumption of dietary compounds, such as phytate, that interfere with iron uptake. Phytate, which commonly occurs in plant foods based on cereal grains and seeds, may bind to iron and thereby interfere with iron absorption. In the present study, an enzyme which degrades phytate was added to a high-phytate diet fed to young piglets that had sub-optimal amounts of hemoglobin, the component of red blood cells that carries oxygen. The enzyme, phytase, degraded the phytate in the diet and the piglets absorbed and used the iron for hemoglobin repletion. Understanding of factors that improve or promote iron absorption in people at risk should lead to better utilization of dietary iron and thereby improve the nutritional health of people.

Technical Abstract: The efficacy of phytase in releasing phytate-bound Fe and P from soybean meal in vitro and in improving dietary Fe bioavailability for hemoglobin repletion in young anemic pigs were examined. In experiment 1, soybean meal was incubated in vitro with either 0, 400, 800 or 1200 U of phytase (Natuphos, BASF, Mt. Olive, NJ) at 37o for 4 h; P concentrations in the supernatant increased in a dose-dependent manner but Fe concentration only increased in response to 1200 U of phytase. In experiment 2, 12 anemic piglets were fed either a high-phytate (1.34%) corn-soybean meal basal diet alone, the basal diet plus 50 mg Fe/kg diet, or the basal diet plus phytase (1200 U/kg diet) for 4 wk. In experiment 3, 20 anemic piglets were fed a corn-soybean meal diet (1.18% phytate) that also contained animal protein provided as whey concentrate (3.0%), or the corn-soy-whey diet plus either supplemental Fe (70 mg/kg diet), supplemental phytase (1200 U Natuphos), or ra new phytase developed in our laboratory (1200 U/kg diet). The phytase supplemented diets used in experiment 3 did not contain inorganic P. In both experiment 2 and 3, piglets provided dietary phytase had increased hemoglobin concentrations and packed cell volumes compared to the unsupplemented control groups. Moreover, hemoglobin concentration in the phytase-supplemented piglets was similar to that in animals provided supplemental Fe. It appears that both sources of phytase effectively degraded phytate in the diets and made dietary iron available for hemoglobin repletion in young, anemic pigs.