Further Evaluation of the Available Phosphorus Requirement of Laying Hens and Methods for Improving the Availability of Phosphorus in Feedstuffs for Poultry

116 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2002.A final laying hen experiment was conducted to evaluate the efficacy of phytase for increasing amino acid utilization of three different laying hen diets. The results indicated that 300 units phytase/kg did not improve amino acid digestibility in laying hen diets containing corn, soybean meal, meat and bone meal and wheat middlings. Chicks were utilized to evaluate the effects of combinations of citric acid (3--4%), phytase (300 units/kg), and 1alpha-hydroxycholecalciferol (5--15 mug/kg) on phytate P utilization in corn-soybean meal P-deficient diets. All compounds improved phytate-P utilization and the effects were generally additive, with some possible synergism between citric acid and 1alpha-hydroxycholecalciferol. Bioavailable P release for citric acid, phytase and 1alpha-hydroxycholecalciferol was calculated to be 0.03, 0.02, and 0.04% P, respectively, and 0.12% P for the combination of all three compounds.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD