Phytate utilization and phosphorus excretion by broiler chickens fed diets containing cereal grains varying in phytate and phytase content

• Published in: Animal feed science and technology 2008-09, Vol.146 (1), p.160-168
• Main Authors: Leytem, A.B., Willing, B.P., Thacker, P.A.
• Format: Article
• Language: English
• Subjects: agricultural soils; Animal productions; antinutritional factors; barley; Biological and medical sciences; broiler chickens; broiler feeding; corn; digesta; Endogenous phytase; enzyme activity; excreta; experimental diets; Feed and pet food industries; feed conversion; feed grains; Food industries; Fundamental and applied biological sciences. Psychology; high fat diet; Hordeum vulgare; mutants; NMR; oats; Phosphorus; phytases; Phytate degradation; phytic acid; Poultry; poultry manure; Terrestrial animal productions; Vertebrates; Zea mays
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/j.anifeedsci.2007.11.006

Eighty, 12-day-old, male broiler chicks, were fed one of four diets to determine the effects of feeding grains varying in phytate phosphorus (P) and intrinsic phytase activity on ileal and excreta P digestibility and composition. The diets contained approximately 970.7 g grain kg −1 (maize, high fat–low lignin oat, normal barley or low-phytate barley) with the cereal supplying the sole source of dietary P. The diets were fed for a 7-day acclimation period followed by a 2 day excreta collection while ileal digesta was collected at slaughter on day 21. The coefficients of ileal apparent digestibility (CIAD) for P and phytate P ranged from 0.79 (normal barley) to 0.86 (maize and low-phytate barley) and 0.76 (low-phytate barley) to 0.89 (maize), respectively. The CIAD for phytate P was significantly greater in the maize and high fat–low lignin oat diets, while the low-phytate barley diet had the lowest coefficient (P>0.002). The coefficients of total tract apparent digestibility (CTTAD) for P and phytate P ranged from 0.25 (maize) to 0.35 (low-phytate barley) and 0.90 (maize and low-phytate barley) to 0.96 (high fat–low lignin oat), respectively, with no significant differences between diets. There was very little phytate P in excreta regardless of the type of grain fed (