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 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 Cheng, X. CH. Search for Related Content PubMed PubMed Citation Articles by Liu, N. Articles by Cheng, X. CH.

Effects of Phytate and Phytase on the Performance and Immune Function of Broilers Fed Nutritionally Marginal Diets

N. Liu^*, Y. J. Ru, A. J. Cowieson, F. D. Li^*,1 and X. CH. Cheng

^* Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China, 730070; Danisco Animal Nutrition, Science Park III, Singapore, 117525; Danisco Animal Nutrition, Marlborough, Wiltshire, SN8 1XN, United Kingdom; and College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China, 471003

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

The effects of phytate and phytase on broiler performance and cellular and humoral immunity was assessed by using 504 Cobb 500 female broilers fed nutritionally marginal diets. At 1 d of age, the chicks were randomly allocated to 6 treatments in a 2 x 3 factorial arrangement including 2 levels of phytate P (0.22 or 0.44%) and 3 dose rates of an Escherichia coli-derived phytase [0, 500, or 1,000 phytase units (FTU)/kg of feed]. Both low- and high-phytate diets were corn and soy based with the same nutritional specifications (AME 2,900 kcal/kg, CP 21.00%, Ca 0.78%, and nonphytate P0.28%), differing only in the concentration of phytate P. The immune status of birds was measured at 14, 21, and 28 d of age. The results revealed that phytase improved feed intake, BW, and feed conversion ratio (P < 0.05), whereas high dietary phytate depressed bird performance (P < 0.05). There was no interaction between phytate and phytase on bird performance. Feeding phytase increased the percentages of erythrocyte rosette-forming cells and erythrocyte-antibody complement cells by 3.03 and 1.83% at d 21, and by 2.76 and 2.20% at d 28, respectively (P < 0.05). The percentages of CD4⁺CD8⁺ T lymphocyte subsets were also increased by phytase (P < 0.05), without affecting the ratio of CD4⁺ and CD8⁺. The levels of intestinal secretory IgA were improved with phytase at d 14, 21, and 28 (P < 0.05). Antibodies against Newcastle disease virus vaccine were enhanced at d 21 and 28 in the high-phytate diets with phytase addition (P < 0.05). Increasing the phytase dose to 1,000 FTU/kg did not improve immune function further than 500 FTU/kg. The results suggest that application of phytase in nutritionally marginal diets could enhance lymphocyte numbers and the seral and mucosal antibodies of 1- to 28-d-old broilers, suggesting that both phytate and phytase may have a role in gastrointestinal health and immune competence.

Key Words: phytate • phytase • immunity • broiler

This article has been cited by other articles:

				N. Liu, Y. J. Ru, F. D. Li, and A. J. Cowieson Effect of diet containing phytate and phytase on the activity and messenger ribonucleic acid expression of carbohydrase and transporter in chickens J Anim Sci, December 1, 2008; 86(12): 3432 - 3439. [Abstract] [Full Text] [PDF]