The development of feedstuff retainable phosphorus values for broilers

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

Presently, phosphorus requirements are based on consumption of nonphytate phosphorus (NPP), which does not account for the fact that NPP may not be completely available and that phytate phosphorus can be partially utilized to fulfill phosphorus requirements. Phosphorus retention values for feed ingredients, accounting for NPP and phytate phosphorus, and total retainable phosphorus requirements are needed to formulate diets that meet the phosphorus requirements of poultry but that do not result in excessive amounts of phosphorus in poultry excreta. A bioassay was conducted to determine retention of phosphorus from calcium phosphates. Eight levels of a reagent-grade monocalcium phosphate, monohydrate, (MCP) were added to a cornsoy, semi-synthetic basal diet containing an acid-insoluble ash marker and offered to individually caged 10-d-old male broilers. After acclimation to the diets for 3 d, excreta were collected for 48 h. Diet and excreta samples were analyzed for total phosphorus, phytate phosphorus, and acid insoluble ash. Retentions of the basal total, NPP, and phytate phosphorus were determined to be 43.2, 65.5, and 32.3%, respectively. Retention of the phosphorus from different phosphorus sources was determined to be dependent on the amount of source included in the diet. The maximum retentions of total phosphorus, NPP, and phosphorus from MCP for the basal-MCP test diets were 67.6, 80.2, and 98%, respectively. The maximum retention of dietary retainable phosphorus occurred with a 2:1 ratio of 0.48% calcium and 0.24% retainable phosphorus. The retainable phosphorus intakes for 10-to-15-d-old broilers required to provide a steady physiological state was 108 mg/d, as determined by two-line regression analysis. Retainable phosphorus requirements based on segmented line regression analysis using bone strength measurements for 0-to-3-wk-old chicks and 3-to-6-wk-old broilers were 0.39 and 0.30%, respectively.

This article has been cited by other articles:

				M. K. Manangi and C. N. Coon Phytate Phosphorus Hydrolysis in Broilers in Response to Dietary Phytase, Calcium, and Phosphorus Concentrations Poult. Sci., August 1, 2008; 87(8): 1577 - 1586. [Abstract] [Full Text] [PDF]

				C. N. Coon, S. Seo, and M. K. Manangi The Determination of Retainable Phosphorus, Relative Biological Availability, and Relative Biological Value of Phosphorus Sources for Broilers Poult. Sci., May 1, 2007; 86(5): 857 - 868. [Abstract] [Full Text] [PDF]

				N. Ziaei, J. H. Guy, S. A. Edwards, P. J. Blanchard, J. Ward, and D. Feuerstein Effect of Gender on Factors Affecting Excreta Dry Matter Content of Broiler Chickens J. Appl. Poult. Res., January 1, 2007; 16(2): 226 - 233. [Abstract] [Full Text] [PDF]

				M. K. Manangi and C. N. Coon Evaluation of Phytase Enzyme with Chicks Fed Basal Diets Containing Different Soybean Meal Samples J. Appl. Poult. Res., January 1, 2006; 15(2): 292 - 306. [Abstract] [Full Text] [PDF]