Effects of Phytase Supplementation of Diets with Two Tiers of Nutrient Specifications on Growth Performance and Protein Efficiency Ratios of Broiler Chickens

  • Selle, P.H. (Faculty of Veterinary Science, The University of Sydney) ;
  • Ravindran, V. ( ;
  • Pittolo, P.H. (Weston Animal Nutrition) ;
  • Bryden, W.L. (School of Animal Studies, The University of Queensland)
  • 투고 : 2002.11.14
  • 심사 : 2003.04.16
  • 발행 : 2003.08.01


In two feeding experiments male and mixed-sex broiler chicks were offered diets based on sorghum and a wheatsorghum blend with two tiers of nutrient specifications, without and with microbial phytase (600 and 800 FTU/kg), from 7-25 and 1-42 days post-hatch, respectively. The nutrient specifications for protein, amino acids, energy density and phosphorus (P) of standard diets were reduced to formulate the modified diets on a least-cost basis. Calculated differences in nutrient specifications between standard and modified diets ranged from 14.3 to 17.1 g/kg crude protein, 0.24 to 0.40 MJ/kg apparent metabolisable energy (AME) and 1.06 to 1.20 g/kg available P. In both experiments, reduced nutrient specifications had a negative impact on growth rates and feed efficiency and phytase supplementation had a positive influence on growth performance and protein efficiency ratios (PER). Phytase addition to the less expensive, modified diets either partially or entirely compensated for reduced growth performance and, consequently, feed costs per kg of live weight gain were reduced. In Experiment 1, phytase increased (p<0.001) nitrogen-corrected AME (AMEn) from 15.39 to 15.89 MJ/kg dry matter. For nitrogen (N) retention there was an interaction (p<0.05) between diet type and phytase as the effects of phytase on N retention were more pronounced in the modified diets, with an increase from 0.512 to 0.561. These results demonstrate the positive effects of phytase on protein and energy utilisation, in addition to its established liberation of phytate-bound P and illustrate the feasibility of assigning nutrient replacement values to the feed enzyme for consideration in least-cost ration formulations. Further work is, however, required to define the most appropriate reductions in nutrient specifications in association with phytase supplementation.


  1. Cabahug, S., V. Ravindran, P. H. Selle and W. L. Bryden. 1999. Response of broiler chickens to microbial phytase as influenced by dietary phytic acid and non-phytate phosphorus levels. I. Effects on bird performance and toe ash content. Brit. Poult. Sci. 40:660-666.
  2. Camden, B. J., P. C. H. Morel, D. V. Thomas, V. Ravindran and M. R. Bedford. 2001. Effectiveness of exogenous microbial phytase in improving the bioavailabilities of phosphorus and other nutrients in maize-soya-bean meal diets for broilers. Anim. Sci. 73:289-297.
  3. Kies, A. K., K. H. F. van Hemert and W. C. Sauer. 2001. Effect of phytase on protein and amino acid digestibility and energy utilisation. World's Poult. Sci. J. 57:109-126.
  4. Ravindran, V. 1995. Phytases in poultry nutrition. An overview. In: Proceedings of the Australian Poultry Science Symposium. Vol. 7:135-139.
  5. Peter, C. M. and D. H. Baker. 2001. Microbial phytase does not improve protein-amino acid utilization in soybean meal fed to young chickens. J. Nutr. 131:1792-1797.
  6. Boling-Frankenbach, S. D., C. M. Peter, M. W. Douglas, J. L. Snow, C. M. Parsons and D. H. Baker. 2001. Efficacy of phytase for increasing protein efficiency ratios of feed ingredients. Poult. Sci. 80:1578-1584.
  7. Hill, F. W. and Anderson, D. L. 1958. Comparison of metabolisable energy and productive energy determination with growing chicks. J. Nutr. 64:587-604.
  8. Kies, A., K. van Hemert, P. Selle and P. Kemme. 1997. The protein effect of phytase. Feed Compounder 17:15-21.
  9. Ravindran, V., S. Cabauhg, G. Ravindran and W. L. Bryden. 1999. Influence of microbial phytase on apparent ileal digestibility in feedstuffs for broilers. Poult. Sci. 78:699-706.
  10. Selle, P. H., D. J. Cadogan, R. G. Campbell and A. R. Walker. 1997. Effects of phytates and phytase on feed conversion ratios of weaner pigs. In: Manipulating Pig Production VI (Ed. P. D. Cranwell). Australasian Pig Science Association, Werribee, Australia. p. 244.
  11. Selle, P. H., V. Ravindran, R. A. Caldwell and W. L. Bryden. 2000. Phytate and phytase: Consequences for protein utilisation. Nutr. Res. Rev. 13:255-278.
  12. Sweeney, R. A. 1989. Generic combustion methods for determination of crude protein in feeds: Collaborative study. J. A. O. A. C. 72:770-774.
  13. Cadogan, D. J., P. H. Selle, R. G. Campbell and A. R. Walker. 1997. Effects of dietary phytate phosphorus and microbial phytase on the performance of weaner pigs. In: Manipulating Pig Production VI (Ed. P. D. Cranwell). Australasian Pig Science Association, Werribee, Australia. p. 245.
  14. Ravindran, V., S. Cabauhg, G. Ravindran, P. H. Selle and W. L. Bryden. 2000. Response of broiler chickens to microbial phytase as influenced by dietary phytic acid and non-phytate phosphorus levels. II. Effects on apparent metabolisable energy, nutrient digestibility and nutrient retention. Br. Poult. Sci. 41:193-200.
  15. Peter, C. M., Y. Han, J. L. Boling-Frankenbach, C. M. Parsons and D. H. Baker. 2000. Limiting order of amino acids and the effects of phytase on protein quality in corn gluten meal fed to young chicks. Poult. Sci. 78:2150-2156.
  16. Potter, L. M. 1988. Bioavailability of phosphorus from various phosphates based on body weight and to ash measurements. Poult. Sci. 67:96-102.
  17. Ravindran, V., P. H. Selle, G. Ravindran, P. C. H. Morel, A. K. Kies, and W. L. Bryden. 2001. Microbial phytase improves performance, apparent metabolizable energy, and ileal amino acid digestibility of broilers fed a lysine-deficient diet. Poult. Sci. 80:338-344.

피인용 문헌

  1. Nutrient utilization and manure P excretion in growing pigs fed corn-barley-soybean based diets supplemented with microbial phytase vol.80, pp.1, 2009,
  2. Amino acid digestibility and poultry feed formulation: expression, limitations and application vol.39, pp.suppl spe, 2010,
  3. Effects of a thermostable phytase on the growth performance and bone mineralization of broilers vol.21, pp.3, 2012,
  4. Nutritive value of vegetable protein diets for broiler chickens and selection of diets containing different vegetable or animal proteins vol.71, pp.01, 2015,
  5. Genetic variability of metabolic characteristics in chickens selected for their ability to digest wheat1 vol.91, pp.6, 2013,
  6. Influence of Dietary Phytate and Exogenous Phytase on Amino Acid Digestibility in Poultry: A Review vol.43, pp.2, 2006,
  7. Performance of Broiler Chickens Fed Low Non Phytate Phosphorus Diets Supplemented with Microbial Phytase vol.44, pp.3, 2007,
  8. Effect of reconstitution of sorghum with or without enzymes on production performance and immunocompetence in broiler chicken vol.89, pp.6, 2009,