caa a22 4500 397568231 CHVBK 20180308164834.0 cr unu---uuuuu 161202e199602 xx s 000 0 eng 10.3382/ps.0750240 doi (NATIONALLICENCE)oxford-10.3382/ps.0750240 Improving Phytate Phosphorus Availability in Corn and Soybean Meal for Broilers Using Microbial Phytase and Calculation of Phosphorus Equivalency Values for Phytase [Elektronische Daten] [Z. YI, E. T. KORNEGAY, V. RAVINDRAN, D. M. DENBOW] Two experiments were conducted to determine the effectiveness of Natuphos® phytase for improving P availability of soybean meal-based semi-purified diets (SP, Experiments 1 and 2) and corn-soybean meal-based diets (CS, Experiment 2) fed to broilers (1 to 21 d). There were 360 and 288 birds fed the SP diets in Experiments 1 and 2, respectively, and 288 birds were fed the CS diets in Experiment 2. Phosphorus equivalency values for phytase were calculated. The basal diets were formulated to contain 0.27% nonphytate P (nP); the SP basal diet contained 0.45% total P (tP) that included 0.17% P as defluorinated phosphate; the CS basal diet contained 0.51% tP that contained 0.12% P as defluorinated phosphate. Both basal diets were supplemented with defluorinated phosphate to provide 0.36, 0.45, or 0.54% nP or with 350, 700, or 1,050 U of phytase/kg diets. Supplementing defluorinated phosphate and phytase linearly increased BW gain (P < 0.001), feed intake (P < 0.001), and percentage ash of dried toes (P < 0.01). Phytase addition increased apparent retention of P (P < 0.02), Ca (P < 0.005 in Experiment 2), and N (P < 0.06 in Experiment 2 for CS), increased apparent digestibility of DM (P < 0.04), and linearly decreased (P < 0.005) P excretion. In comparison to the 0.45% nP diet, P excretion was reduced 42 to 51% by addition of phytase. The addition of defluorinated phosphate linearly decreased apparent retention of P (P < 0.02) and Ca (P < 0.005 in Experiment 2), and increased P excretion (P < 0.007). The average of released P by phytase calculated by solving nonlinear or linear response equations of P and phytase levels for SP diets in Experiments 1 and 2 gave a P equivalency value of 1 g P = 1,146 U of phytase. The P equivalency value for CS diets fed only in Experiment 2 was 785 U of phytase = 1 g P as defluorinated phosphate. These studies show that microbial phytase is effective for improving P availability and for decreasing P excretion. Added phytase can also increase Ca and N retention. © 1996 Poultry Science Association, Inc. Metabolism and Nutrition nationallicence phosphorus nationallicence phytase nationallicence broiler nationallicence equivalency values nationallicence YI Z. aut KORNEGAY E. T. 1To whom correspondence should be addressed. aut RAVINDRAN V. aut DENBOW D. M. aut Poultry Science Oxford University Press 75/2(1996-02), 240-249 0032-5791 75:2<240 1996 75 ps https://doi.org/10.3382/ps.0750240 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.3382/ps.0750240 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- YI Z. aut NATIONALLICENCE 700 1- KORNEGAY E. T. 1To whom correspondence should be addressed aut NATIONALLICENCE 700 1- RAVINDRAN V. aut NATIONALLICENCE 700 1- DENBOW D. M. aut NATIONALLICENCE 773 0- Poultry Science Oxford University Press 75/2(1996-02), 240-249 0032-5791 75:2<240 1996 75 ps Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford