Phytase improves iron bioavailability for hemoglobin synthesis in young pigs.

Abstract

Dietary phytase supplementation improves bioavailabilities of phytate-bound minerals such as P, Ca, and Zn to pigs, but its effect on Fe utilization is not clear. 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 was examined. In Exp. 1, soybean meal was incubated at 37 degrees C for 4 h with either 0, 400, 800, or 1,200 units (U) of phytase/kg, and the released Fe and P concentrations were determined. In Exp. 2, 12 anemic, 21-d-old pigs were fed either a strict vegetarian, high-phytate (1.34%) basal diet alone, or the diet supplemented with 50 mg Fe/kg diet (ferrous sulfate) or phytase at 1,200 U/kg diet (Natuphos, BASF, Mt. Olive, NJ) for 4 wk. In Exp. 3, 20 anemic, 28-d-old pigs were fed either a basal diet with a moderately high phytate concentration (1.18%) and some animal protein or the diet supplemented with 70 mg Fe/kg diet, or with one of two types of phytase (Natuphos or a new phytase developed in our laboratory, 1,200 U/kg diet) for 5 wk. In Exp. 2 and 3, diets supplemented with phytase contained no inorganic P. In Exp. 1, free P concentrations in the supernatant increased in a phytase dose-dependent fashion (P<.05), whereas free Fe concentrations only increased at the dose of 1,200 U/kg (P<.10). In Exp. 2 and 3, dietary phytase increased hemoglobin concentrations and packed cell volumes over the unsupplemented group; these two measures, including growth performance, were not significantly different than those obtained with dietary supplemental Fe. In conclusion, both sources of phytase effectively degraded phytate in corn-soy diets and subsequently released phytate-bound Fe from the diets for hemoglobin repletion in young, anemic pigs.

Metabolismo do ferro em suínos recebendo dietas contendo fitase, níveis reduzidos de fósforo inorgânico e sem suplemento micromineral e vitamínico

“…de hemoglobina em leitões anêmicos (STAHL et al, 1999). Neste estudo, a fitase não interferiu nos parâmetros de hemoglobina; esta diferença pode ser atribuída à ausência de anemia nos animais testados.…”

Improving human micronutrient nutrition through biofortification in the soil–plant system: China as a case study

“…This model is believed to be the most accurate one, but it is relatively costly to carry out. Young pig models have been used to evaluate the effects of meat on enhancing Fe absorption and the effects of phytase on improving Fe bioavailability for hemoglobin synthesis (Stahl et al 1999). Schaffer et al (2004) have used early-weaned piglets to study the biological effects of using high-Fe rice as feed.…”

Phytase: An Enzyme to Improve Soybean Nutrition

“…Estimated inorganic P/phytase equivalence in animal diets is that 300-600 phytase units/kg of diets can release 0.8 g of digestible P and replace either 1.0 or 1.3 g of P from mono-and dicalcium phosphate, respectively (Ravindram et al, 1995;Esteve-Garcia et al, 2005). Supplemental phytase also improves the availability to farm animals of Ca, Zn or Fe in the soybean meal (Lei et al, 1993c;Lei et al, 1994;Stahl et al, 1999;Jondreville et al, 2005;, 2001. Dephytinization of soy formulas or soybean-derived food products intended for human consumption has also improved bioavailabilities of Fe and Zn (Hurrell, 2003).…”

“…Such findings could be of enormous interest in developing strategies to prevent and improve the recovery of hip fractions associated with osteoporosis in the elderly. Furthermore, phytase supplementation may enhance the availability of other minerals like Ca, Zn, Fe, Cu or Mn that are present in soybean meal but are currently added to swine and poultry diets (Adeola et al, 1995;Lei et al, 1993c;Lei et al, 1994;Rimbach et al, 1997;Stahl et al, 1999). Beneficial effects of phytase on Fe availability from soybean are quite a special issue since soybean consumption appears to affect differently the absorption of heme or non-heme Fe.…”

“…Nevertheless, phytase supplementation is still the most feasible method for improving the phytate-mediated low availability of essential minerals in the corn soybean-based diets. In fact, Stahl et al (1999) found that phytase was effective 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 fed a standard corn-soybean diet. On the other hand, Lynch et al (1985) reported that partial substitution of beef with soy flour reduced the availability of non-heme Fe but significantly improved the percentage of heme Fe absorption, although the net effect appeared to be a modest reduction in the total amount of Fe absorbed.…”