HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yan, F. Articles by Walsroup, P. W. Search for Related Content PubMed Articles by Yan, F. Articles by Walsroup, P. W.

Evaluation of Modified Dietary Phosphorus Levels with and Without Phytase Supplementation on Live Performance and Excreta Phosphorus Concentration in Broiler Diets. 2. Modified Early Phosphorus Levels

Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701

Correspondence: P. W. Waldroup, E-mail: Waldroup{at}uark.edu

Two broiler feeding trials of identical design were conducted to evaluate the use of starter diets with dietary nonphytate phosphorus (NPP) concentrations similar to present NRC or industry usage concentrations to support early skeletal growth, followed by markedly reduced concentrations in grower and finisher periods. In each trial, 4 experimental treatments were compared. One treatment consisted of NRC-recommended concentrations of NPP (NRC); in the second treatment the NPP was 0.05% greater than NRC recommendations to simulate current industry practices (IND). Two other treatments were based on adequate amounts of NPP in starter (0 to 3 wk) diets followed by reduced NPP in grower and finisher diets. The first of these 2 treatments provided the chicks with 0.50, 0.25, and 0.15% NPP for 0 to 3, 3 to 6, and 6 to 9 wk, respectively (MOD). The second of these 2 treatments provided the chicks with 0.40, 0.20, and 0.10% NPP for the same age periods, with the diets supplemented with 1,000 U/kg of phytase (MOD+PHY). Body weight, feed conversion, mortality, tibia ash, and excreta P content were determined at 21, 42, 53, and 63 d of age.

The P content in excreta of birds fed the MOD or MOD+PHY diets was much lower than that of birds fed the NRC or IND diets. Compared with NRC recommended levels, excreta P from chicks during the grower and finisher periods was reduced 21 to 44% by the MOD program and 31 to 56% by the MOD+PHY program. Compared with typical industry concentrations, the excreta P during the grower and finisher periods was reduced 32 to 48% by the MOD program and 41 to 59% by the MOD+PHY program. These reductions in excreta P were obtained with no adverse effects on BW, feed conversion, mortality, or tibia ash. In addition to reducing excreta P, these modifications in dietary P can result in a significant reduction in feed costs.

Key Words: phosphorus • broilers • phytase • eutrophication

This article has been cited by other articles:

				P. Catala-Gregori, V. Garcia, F. Hernandez, J. Madrid, and J. J. Ceron Response of broilers to feeding low-calcium and phosphorus diets plus phytase under different environmental conditions: body weight and tibiotarsus mineralization. Poult. Sci., November 1, 2006; 85(11): 1923 - 1931. [Abstract] [Full Text] [PDF]

				C. A. Fritts and P. W. Waldroup Modified Phosphorus Program for Broilers Based on Commercial Feeding Intervals to Sustain Live Performance and Reduce Total and Water-Soluble Phosphorus in Litter J. Appl. Poult. Res., January 1, 2006; 15(2): 207 - 218. [Abstract] [Full Text] [PDF]