Iron bioavailability in soybean meal as affected by supplemental phytase and 1 alpha-hydroxycholecalciferol.
An Fe depletion-repletion chick bioassay was conducted to determine whether supplemental microbial phytase or 1 alpha-hydroxycholecalciferol (1 alpha-OH D3) would improve the bioavailability of Fe in soybean meal (SBM). Weight gain, hemoglobin, and hematocrit were markedly improved when increasing levels (0, 10, 20, and 80 mg/kg) of Fe from analytical grade ferrous sulfate (FeSO4.7H2O) were added to the Fe-deficient casein-dextrose basal diet containing 20 mg Fe/kg. Addition of 19 mg Fe/kg from SBM to the basal diet improved (P < 0.05) hemoglobin and hematocrit, but the response was less than that obtained from 10 mg Fe/kg from FeSO4.7H2O. Phytase (1,430 units/kg), 1 alpha-OHD3 (10 micrograms/kg), or the combination, added to the SBM-fortified basal diet did not further improve hematocrit or hemoglobin, indicating that Fe bioavailability of SBM was not increased by either of these feed additives. Based on standard-curve methodology, and using hemoglobin as a criterion, the relative bioavailability of Fe was 38.5% for SBM, 21.0% for SBM+phytase, 23.2% for SBM+1 alpha-OHD3, and 29.2% for SBM+phytase+ 1 alpha-OHD3.
Biehl
R R
RR
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
Emmert
J L
JL
Baker
D H
DH
D010832:6-Phytase / Q000008:administration & dosage / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001682:Biological Availability; D002645:Chickens / Q000097:blood / Q000378:metabolism* / Q000502:physiology; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D006400:Hematocrit / Q000662:veterinary; D006454:Hemoglobins / Q000032:analysis; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000494:pharmacology*; D007501:Iron / Q000032:analysis / Q000493:pharmacokinetics*; D016014:Linear Models; D013025:Glycine max / Q000737:chemistry*; D015430:Weight Gain / Q000502:physiology
D006454:Hemoglobins; D006887:Hydroxycholecalciferols; D007501:Iron; D010832:6-Phytase; C008088:alfacalcidol