137 Effects of a Corn-Expressed Phytase on Growth Performance and Bone Ash of Nursery Pigs

• Published in: Journal of animal science 2018-04, Vol.96 (suppl_2), p.73-73
• Main Authors: Knapp, J P, Tsai, T, Broomhead, J N, Chewning, J J, Maxwell, C V
• Format: Article
• Language: English
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky073.135

Abstract This experiment was conducted to determine the optimum level of corn-expressed phytase (CEP; GraiNzyme® Phytase, Agrivida) by evaluating growth performance and metacarpal bone characteristics in nursery pigs fed phosphorus and calcium deficient diets. A total of 288 pigs were blocked by initial BW and allotted to 1 of 6 treatments (8 replicates per treatment). Pens were randomly assigned to dietary treatments. Treatments consisted of: P and Ca adequate diet (PC; NRC 2012); decreased P (0.15%) and Ca (0.1%) diet (NC), and NC plus 500, 1000, or 1500 FYT/kg of CEP or 500 FYT/kg of Ronozyme® Hiphos GT. Pigs were fed a common phase-1 (8d) diet before initiated treatments in phase-2 (14d) and 3 (14d). Pigs were euthanized at termination of phase-3 to collect metacarpal bones for ash determination. Data were analyzed by PROC MIXED procedures of SAS with treatments as fixed effect and initial BW block as random effect. Orthogonal contrasts were performed to determine the effects of increasing CEP. Increasing levels of CEP linearly increased overall ADG (P < 0.01), G:F (P < 0.05), end BW (P < 0.05), and percent bone ash (P < 0.01; Table 1). Pigs fed 500 FYT/kg of CEP had comparable (P > 0.05) or greater (P < 0.05) bone ash weight or percentage, respectively, as compared to pigs fed Hiphos GT. Pigs fed 1000 FYT/kg CEP had equivalent (P > 0.05) percent bone ash as compared to PC fed pigs. Results suggest that pigs fed diets low in P and Ca supplemented with corn-derived phytase performed similar to pigs fed a commercial available phytase and a diet with adequate levels of Ca and P. Table 1. Effect of corn-expressed phytase on overall growth performance and bone ash in nursery pigs FYT/kg Adequate Minerals Reduced Minerals (NC) NC + GraINzyme NC + HiPhos SEM P - Value 500 1000 1500 500 Treatment Linear Quadratic End BW, kg 22.61 21.43 22.87 23.00 23.56 22.49 0.67 0.18 0.01 0.44 ADG, kg/d 0.455 0.421 0.463 0.465 0.483 0.453 0.015 0.10 0.01 0.42 G:F 0.644 0.630 0.638 0.666 0.679 0.663 0.019 0.41 0.04 0.90 Bone Ash, g 1.122d 0.840a 0.984bc 1.037c 1.098cd 0.951b 0.029