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

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed 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 Liu, N. Articles by Ru, Y. J. Search for Related Content PubMed PubMed Citation Articles by Liu, N. Articles by Ru, Y. J.

Efficacy of Phytases on Egg Production and Nutrient Digestibility in Layers Fed Reduced Phosphorus Diets

N. Liu^*, G. H. Liu, F. D. Li^*,1, J. S. Sands, S. Zhang, A. J. Zheng and Y. J. Ru

^* Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China, 730070; Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China, 100081; Danisco Animal Nutrition, Marlborough, Wiltshire, SN8 1XN, United Kingdom; and Danisco Animal Nutrition, Science Park III, Singapore, 117525

¹ Corresponding author: lifd{at}gsau.edu.cn

The effects of phytases on the performance of layers and the ileal nutrient digestibility of corn-, soybean-, and by-product meal-based diets were assessed with 320 Hy-Line brown layers from 23 to 28 wk of age. Layers were grouped randomly into 5 treatments, with 8 replicates per treatment and 8 layers per replicate. The 5 diets consisted of a positive control diet with adequate Ca (3.30%), total P (0.50%), and nonphytate P (NPP; 0.28%), and a negative control diet with Ca reduced by 0.12%, total P reduced by 0.14%, NPP reduced by 0.13%, and 3 phytases (phytase A derived from Aspergillus niger, and phytases B and C derived from Escherichia coli) supplemented at 300 phytase units/kg of feed, respectively. Egg production and feed intake were recorded daily, and eggshell quality and ileal nutrient digestibility were measured at the end of a 6-wk feeding period. The results revealed that the reduction of Ca and P from the positive control diet significantly depressed feed intake, egg mass, eggshell hardness, and the digestibility of N, Ca, P, and amino acids (P < 0.05). Phytase supplementation in the negative control diet improved the digestibility of P and Ca by 11.08 and 9.81% (P < 0.05), respectively, whereas it improved the digestibility of amino acids by 2 to 8% (P < 0.05). However, the digestibility of most amino acids was not restored to the levels of the positive control diet by the application of phytases. Supplementing phytases in the negative control diet improved the rate of lay, egg mass, and egshell quality to the levels of birds fed the positive control diet. These results suggest that supplementing phytases can improve the digestibility not only of Ca and P, but also of amino acids in layers fed a corn-, soybean-, and by-product-based diet.

Key Words: phytase • nutrient • digestibility • layer

This article has been cited by other articles:

				N. Liu, Y. J. Ru, A. J. Cowieson, F. D. Li, and X. CH. Cheng Effects of Phytate and Phytase on the Performance and Immune Function of Broilers Fed Nutritionally Marginal Diets Poult. Sci., June 1, 2008; 87(6): 1105 - 1111. [Abstract] [Full Text] [PDF]