Effect of supplementing graded concentrations of non-phytate phosphorus on performance, egg quality and bone mineral variables in White Leghorn layers

• Published in: British poultry science Vol. 60; no. 1; pp. 56 - 63
• Main Authors: Rama Rao, S. V., Raju, M. V. L. N., Paul, S. S., Prakash, B.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 02.01.2019
• Subjects: Animal Feed - analysis; Animal Nutritional Physiological Phenomena - drug effects; Animals; Calcification, Physiologic - drug effects; Chickens - physiology; Diet - veterinary; Dietary Supplements - analysis; Dose-Response Relationship, Drug; Egg production; Egg Shell - chemistry; Egg Shell - drug effects; Female; layers; non-phytate phosphorus; Ovum - drug effects; Ovum - physiology; Phosphorus, Dietary - administration & dosage; Phosphorus, Dietary - metabolism; shell quality; layers; shell quality; non-phytate phosphorus; Egg production
• ISSN: 0007-1668; 1466-1799
• DOI: 10.1080/00071668.2018.1537478

1. An experiment was conducted to determine optimal non-phytate phosphorus (NPP) concentrations for White Leghorn (WL) layers (22-72 weeks) fed diet containing 38 g Ca/kg. 2. Eight diets with graded concentrations (1.5-3.25 g/kg in increments of 0.25 g) of NPP were prepared. Each diet was fed to eight pen replicates containing 88 birds in each. Performance data was evaluated in three different phases (phase I-22-37 weeks, phase II-38-53 weeks and phase III-54-72 weeks). Optimum levels of NPP were determined by fitting a quadratic polynomial (QP) regression model. 3. Egg production (EP) was not affected (P = 0.059) by the concentration of NPP and interaction between NPP and diet phase was non-significant, indicating that the lowest concentration (1.5 g/kg diet) of NPP used in the study was adequate across the three phases. However, EP was influenced by phase (P < 0.001). 4. Optimum concentration of NPP for feed intake (FI) was estimated to be 1.5, 1.71 and 2.40 g/kg diet during phases I, II and III, respectively. FI per egg mass (EM) or feed efficiency (FE) responded quadratically with NPP and also differed significantly between phases. Optimum concentration of NPP for FE during phases I, II and III was 1.5, 2.56 and 2.32 g/kg diet, respectively. 5. Egg weight (EW), EM, shell weight and thickness were not affected by NPP concentration although all of these variables (except shell weight) were influenced by phases. 6. Breaking strength of tibia and Ca contents in tibia ash were not affected by the concentration of NPP, but bone ash and P contents in tibia ash were influenced (P < 0.001) by NPP. Predicted optimal concentrations of NPP for responses for tibia ash at 44 or 72 weeks, tibia ash P at 44 weeks and tibia ash P at 72 weeks were 1.55, 2.63 and 1.5 g/kg diet, respectively. 7. Based on the results, it was concluded that WL layers required 1.5 g, 2.63 g and 2.4 g, respectively/kg diet during phase I, II and III with the calculated daily intake of 137.3, 278.3 and 262 mg NPP/b/d.