The effect of different levels of nonphytate phosphorus with and without phytase on the performance of four strains of laying hens

Department of Animal Science, Cornell University, Ithaca, New York 14853, USA. kk33@cornell.edu

A 4 x 7 factorial experiment was conducted to determine the effect of different nonphytate phosphorus (NPP) regimens with and without phytase on performance of four strains of laying hens. The strains used were Babcock B300, DeKalb Delta White, Hy-Line W36, and ISA-White. The birds of T1 (Treatment 1), control diet, were fed a diet with 0.45% NPP for the entire experiment (20 to 63 wk of age). The birds of T2 were fed a NPP regimen of 0.25% for Phase 1 (20 to 35 wk of age), 0.2% for Phase 2 (36 to 51 wk of age), and 0.15% for Phase 3 (52 to 63 wk of age). The birds of T3 and T4 were fed a NPP regimen similar to T2 plus 150 or 300 units phytase/kg diet, respectively. The birds of T5 were fed a NPP regimen of 0.2, 0.1, and 0.1% for Phases 1, 2, and 3, respectively. The birds on T6 and T7 were fed a NPP regimen similar to T5, with 150 and 300 units phytase/kg diet, respectively. The criteria for evaluating the effect of dietary treatments were production performance, shell quality, bone ash, and total P excretion. Production traits were drastically reduced and mortality was drastically increased when the birds of T5 were fed a diet with 0.1% NPP during Phase 2 (36 to 51 wk of age). Increasing the NPP level of this treatment from 0.1 to 0.45% during Phase 3 restored the production traits almost to the control level during this phase of the experiment. The NPP regimen of 0.2-0.1-0.1% plus either level of phytase (T6 and T7) restored most of the traits for the entire experiment to the control level (T1), except egg production (EP) and the nonprolapse mortality. Bone ash also remained significantly lower than the control group with this NPP regimen plus the higher level of phytase (T7). Production traits were reduced, and nonprolapse mortality was increased due to the use of a NPP regimen of 0.25-0.2-0.15% without phytase (T2) for the entire experiment. The NPP regimen of 0.25-0.2-0.15% plus the lower level of phytase (T3) restored all the traits except EP to the control level for the entire experiment. The only treatment that maintained performance of all the strains comparable to their controls for the entire experiment was a NPP regimen of 0.25-0.2-0.15% plus the higher level of phytase (T4). Total P excretion of birds fed this NPP regimen was reduced by 55.6% as compared to the control group. The data generally indicated that the higher level of phytase was more effective than the lower level in restoring the performance of birds fed the low-P diets to the control level. Numerous interactions existed among strain x diet for various traits throughout the experiment, indicating the NPP requirement for maintaining production performance may be different among strains.

This article has been cited by other articles:

				U. P. P. Pillai, V. Manoharan, A. Lisle, X. Li, and W. Bryden Phytase Supplemented Poultry Diets Affect Soluble Phosphorus and Nitrogen in Manure and Manure-amended Soil J. Environ. Qual., June 23, 2009; 38(4): 1700 - 1708. [Abstract] [Full Text] [PDF]

				F. G. Silversides and M. Hruby Feed formulation using phytase in laying hen diets J. Appl. Poult. Res., January 1, 2009; 18(1): 15 - 22. [Abstract] [Full Text] [PDF]

				W. Powers and R. Angel A Review of the Capacity for Nutritional Strategies to Address Environmental Challenges in Poultry Production Poult. Sci., October 1, 2008; 87(10): 1929 - 1938. [Abstract] [Full Text] [PDF]

				M. Newell-McGloughlin Nutritionally Improved Agricultural Crops Plant Physiology, July 1, 2008; 147(3): 939 - 953. [Full Text] [PDF]

				N. Liu, G. H. Liu, F. D. Li, J. S. Sands, S. Zhang, A. J. Zheng, and Y. J. Ru Efficacy of Phytases on Egg Production and Nutrient Digestibility in Layers Fed Reduced Phosphorus Diets Poult. Sci., November 1, 2007; 86(11): 2337 - 2342. [Abstract] [Full Text] [PDF]

				W. Wu-Haan, W. J. Powers, C. R. Angel, C. E. Hale III, and T. J. Applegate Effect of an Acidifying Diet Combined with Zeolite and Slight Protein Reduction on Air Emissions from Laying Hens of Different Ages Poult. Sci., January 1, 2007; 86(1): 182 - 190. [Abstract] [Full Text] [PDF]