Abelson, P. H. 1999. A potential phosphate crisis. Science 283:2015.
Adeola, O., B. V. Lawrence, A. L. Sutton and T. R. Cline. 1995. Phytase-induced changes in mineral utilization in zincsupplemented diets for pigs. J. Anim. Sci. 73:3384-3391.
Adeola, O., J. S. Sands, P. H. Simmins and H. Schulze. 2004. The efficacy of an Escherichia coli-derived phytase preparation. J. Anim. Sci. 82:2657-2666.
AOAC. 1990. Official methods of analysis. 15th ed. Assoc. Off. Anal. Chem., Arlington, VA.
Augspurger, N. R., D. M. Webel, X. G. Lei and D. H. Baker. 2003. Efficacy of an E. coli phytase expressed in yeast for releasing phytate-bound phosphorus in young chicks and pigs. J. Anim. Sci. 81:474-483.
Boyd, R. D., D. Hall and J. F. Wu. 1983. Plasma alkaline phosphatase as a criterion for determining biological availability of phosphorus for swine. J. Anim. Sci. 57:396-401.
Broadus, A. E. 1981. Endocrinology and Metabolism. pp. 1008- 1009. McGraw-Hill Book Co., Inc., New York.
Engelen, A. J., F. C. van der Heeft, P. H. Randsdorp, W. A. Somers, J. Schaefer and B. J. van der Vat. 2001. Determination of phytase activity in feed by a colorimetric enzymatic method: Collaborative inter-laboratory study. J. AOAC Int. 84:629-633.
Harper, A. F., E. T. Kornegay and T. C. Schell. 1997. Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility and bone mineralization and reduces phosphorus excretion. J. Anim. Sci. 75:3174-3186.
Hoppe, P. P. and G. Schwarz. 1993. Experimental approaches to establish the phosphorus equivalency of Aspergillus nigerphytase in pigs. Proceedings, 1st Symposium Enzymes in Animal Nutrition. Kartause Ittingen, Switzerland, pp. 187-191.
Jendza, J. A., R. N. Dilger, S. A. Adedokun, J. S. Sands and O. Adeola. 2005. Escherichia coli phytase improves growth performance of starter, grower and finisher pigs fed phosphorus-deficient diets. J. Anim. Sci. 83:1882-1889.
Jendza, J. A., R. N. Dilger, J. S. Sands and O. Adeola. 2006. Efficacy and equivalency of an Escherichia coli-derived phytase for replacing inorganic phosphorus in the diets of broiler chickens and young pigs. J. Anim. Sci. 84:3364-3374.
Jendza, J. A. and O. Adeola. 2009. Water-soluble phosphorus excretion in pigs fed diets supplemented with microbial phytase. Anim. Sci. 80:296-304.
Johnston, S. L., S. B. Williams, L. L. Southern, T. D. Bidner, L. D. Bunting, J. O. Matthews and B. M. Olcott. 2004. Effect of phytase addition and dietary calcium and phosphorus levels on plasma metabolites and ileal and total-tract nutrient digestibility in pigs. J. Anim. Sci. 82:705-714.
Letourneau-Montminy, M. P., A. Narcy, M. Magnin, D. Sauvant, J. F. Bernier, C. Pomar and C. Jondreville. 2010. Effect of reduced dietary calcium concentration and phytase supplementation on calcium and phosphorus utilization in weanling pigs with modified mineral status. J. Anim. Sci. 88:1706-1717.
Lindberg, J. E., K. Lyberg and J. Sands. 2007. Influence of phytase and xylanase supplementation of a wheat-based diet on ileal and total tract digestibility in growing pigs. Livest. Sci. 109: 268-270.
Liu, J., D. W. Bollinger, D. R. Ledoux and T. L. Veum. 1998. Lowering the dietary calcium to total phosphorus ratio increases phosphorus utilization in low-phosphorus cornsoybean meal diets supplemented with microbial phytase for growing-finishing pigs. J. Anim. Sci. 76:808-813.
Omogbenigun, F. O., C. M. Nyachoti and B. A. Slominski. 2003. The effect of supplementing microbial phytase and organic acids to a corn-soybean meal based diet fed to early-weaned pigs. J. Anim. Sci. 81:1806-1813.
Paditz, K., H. Kluth and M. Rodehutscord. 2004. Relationship between graded doses of three microbial phytases and digestible phosphorus in pigs. Anim. Sci. 78:429-438.
Radcliffe, J. S., R. S. Pleasant and E. T. Kornegay. 2006. Estimating equivalency values of microbial phytase for amino acids in growing and finishing pigs fitted with steered ileocecal valve cannulas. J. Anim. Sci. 84:1119-1129.
Selle. P. H. and V. Ravindran. 2008. Phytate-degrading enzymes in pig nutrition. Livest. Sci. 113:99-122.
Stein, H. H., C. F. Shipley and R. A. Easter. 1998. Technical note: A technique for inserting a T-cannula into the distal ileum of pregnant sows. J. Anim. Sci. 76:1433-1436.
Veum, T. L., D. W. Bollinger, C. E. Buff and M. R. Bedford. 2006. A genetically engineered Escherichia coli phytase improves nutrient utilization, growth performance and bone strength of young swine fed diets deficient in available phosphorus. J. Anim. Sci. 84:1147-1158.
Veum, T. L. and M. R. Ellersieck. 2008. Effect of low doses of Aspergillus niger phytase on growth performance, bone strength and nutrient absorption and excretion by growing and finishing swine fed corn-soybean meal diets deficient in available phosphorus and calcium. J. Anim. Sci. 86:858-870.
Williams, C. H., D. J. David and O. Iismaa. 1962. The determination of chromic oxide in faeces sample y atomic absorption spectrophotometry. J. Agric. Sci. 59:381-385.