• Salah Khatir Jubarah University of Juba
  • Milton L. Melingasuk University of Juba
  • Rizig E. Loma Marial Luo Livestock Training Centre, Tonj State, South Suda
Keywords: Phytate-P, Phytase, Dietary-wetness, Inorganic phosphorus, in vitro


Dietary wetness is envisaged to augment phytate hydrolysis through enhanced phytate accessibility to phytase, since phytate degradation is water-mediated. In determining the influence of dietary wetness with supplementary phytase on phytate-P availability, four plant-based growers diets were formulated, containing 0.0, 0.1, 0.2 and 0.3g kg-1 added phytase and with the required phosphorus being entirely phytate-P. Dietary moisture contents were reconstituted by addition of three levels of 0.0, 30 and 60 % distilled-deionised water on Dry Matter basis (DM). Dietary treatments were arranged in a factorial randomized complete block design with three replications. The released inorganic phosphorus was determined at 6hr intervals throughout the 24hr incubation period at 24ºC. The 30% and 60% dietary wetness with added phytases significantly increased (P<0.05) inorganic phosphorus output compared to either 0.0% or wetness without added phytase.  At 6hr of incubation, phytase plus 60% wetness had the highest (P<0.05) inorganic phosphorus, while at 12hr 30% dietary wetness plus phytase yielded the highest inorganic phosphorus (P<0.05). Wetness plus phytase had no pronounced effect (P<0.05) beyond 12hr, except at 24hr (P<0.05). Increasing supplementary phytase in association with dietary wetness significantly (P<0.05) increased inorganic phosphorus output, however, setting wet diets beyond 12hr, produced gases and dietary discoloration.

Author Biographies

Salah Khatir Jubarah, University of Juba

Associate Professors,  Department of Animal Production, College of Natural Resources and Environmental Studies, University of Juba, P.O. Box 82 Juba, South Sudan

Milton L. Melingasuk, University of Juba

Associate Professors,  Department of Animal Production, College of Natural Resources and Environmental Studies, University of Juba, P.O. Box 82 Juba, South Sudan

Rizig E. Loma, Marial Luo Livestock Training Centre, Tonj State, South Suda

Technical Officer, Marial Luo Livestock Training Centre, Tonj State, South Suda


1. Analysis of Agricultural Materials. (1986). A Manual of the Analytical Methods Used by the Agricultural Development and Advisory Service, 3rd Edition. Ministry of Agriculture, Fisheries and Food.
2. Bartnik, M. and Szafranska, I. (1987). Changes in phytate content and phytase activity during germination of some cereals. Journal of Cereal Science 5: 23-28.
3. Bedford, M.R. and Autio, K.A. (1996). Microscopic examination of feed and digestibility from wheat-fed broiler chickens and its relation to bird performance. Poultry Science, 75: (Suppl.1)14.
4. Bedford, M. R. and Schulze, N. (1998). Exogenous enzymes for pigs and poultry. Nutrition Research Reviews 11: 91-114.
5. de Boland, A. R., Ganer, G. B. and Boyd, I. (1975). Identification and properties of phytate in cereal grains and oil seed product. Journal of Agricultural and Food Chemistry 23: 1186-11.
6. Eeckhout, W. and de Paepe, M. (1991). The quantitative effects of an industrial microbial phytase and wheat phytase in the apparent phosphorus absorbability of a mixed feed by piglets. Proceedings of the Fifth Forum of Applied Bio-technology, Part II. University of Gent. Belgium, pp.1643-1646.
7. Fredrikson, M., Alminger, M.L., Carlsson, N.G. and Sandberg, A.S. (2001). Phytate content and phytate degradation by endogenous phytate in pea (Pisum sativum). Journal of Science Food Agriculture., 81: 1139-1144.
8. Genstat 5. (1995). Lawes Agricultural Trust, Rothamsted Experimental Station, Rothamsted Lawes Agricultural Trust.
9. Gomez, K.A. and Gomez, A.A. (1984). Statistical Procedure for Agricultural Research, 2nd Edition, Wilyand Sons, Inc.
10. Hill, K.J. (1971). The physiology of digestion. In: Physiology and Biochemistry of the domestic Fowl, (eds.) Bell D.J. and Freeman B.M., Academic Press. London, UK: 125pp.
11. Irving, G.C.J. (1980). Phytase. In: Inositol Phosphates: their Chemistry, Biochemistry and physiology, (eds.) Cosgrove D.J., Elsevier: Amsterdam.
12. Jubarah, S.K. and Davis, R.H., (2006). Effect of phytate in plant-based diet: Estimation of simultaneous dietary nutrient retention. Verona, Italy, 10 -14 September 2006. http://www.wpsa.com/proceedings/proceedings.html.
13. Ministry of Agriculture, Fisheries and Food., (1974). Poultry Nutrition. Bultrin 174. Her Majesty’s Stationary Office. London.
14. Nelson, T.S. (1976). The hydrolysis of phytate phosphorus by chicks and laying hens. Poultry Science, 55: 2262-2264.
15. Newkirk, R.W. and Classen, H.L. (1997). In vitro hydrolysis of phytate in canola meal with purified and crude sources of phytase, Anim. Feed. Sci. Technol., 72: 315-327.
16. Pointillart, A. (1993). Importance of phytases and cereal phytases in the feeding of pigs, in Enzymes in Nutrition, (eds.) Wenk C. and Bossinger M. Schrifterneriheausdem Institut fur. ETH - Zurich.pp. Animal, 192.
17. Prochaska, L.J. and Piekutowski, W.V. (1994). On the synergistic effects of enzymes in food with enzymes in the human body. A literature survey and analytical report. Medical Hypothesis, 42: 355-362.
18. Scheuermann, S.E., Lantzsch, H.L. and Menke, K.H. (1988). In vitro and in vivo experiment on the hydrolysis of phytate. 2. Activity of plant phytase. Journal of Animal Physiology and Animal Nutrition, 60: 55.
19. Schlemmer, U., Muller, H. and Jany, K.D. (1995). The degradation of phytic acid in legumes prepared by different methods. European Journal of Clinical Nutrition, 49: 207-210.
20. Schöner, F.J., Hoppe, P.P., Schwartz, G. and Wiesche, H. (1993). Effects of microbial phytate and inorganic phosphate in broiler chickens: performance and mineral retention at various calcium levels. Journal of Animal Physiology and Animal Nutrition, 69: 235-244.
21. Simons, P.C.M., Versteegh, H.A., Jongbloed, A.W., Kemme, P.A., Slump, P., Bos, K.D., Wolters, M.G.E., Buedeker, R.F. and Vershoor, G.J. (1990). Improvement of phosphorus availability by microbial phytase in broilers and pigs. British Journal of Nutrition, 64: 525-540.
22. Temperton, H. and Cassidy, J. (1964). Phosphorus requirement of poultry. II. The utilisation of phytin phosphorus by the chicks for growth and bone formation. British Poultry Science, 5: 81-86.
23. Temperton, H., Dudley, F.J. and Pikering, G.H. (1965). Phosphorus requirement of Poultry, V. The effects of feeding growing diets containing no animal protein or supplemental phosphorus. British Poultry Science, 6: 135.
24. Ravindran, V., Bryden, W.L. and Korngegay, E.T. (1995). Phytate: occurrence, bioavailability and implications in poultry nutrition. Poultry and Avian Biology Reviews, 6: 125-14.
25. Yasar, S. and Forbes, J.M. (1999). Performance and gastro-intestinal response of broiler chickens fed on cereal grain-based food soaked in water. British Poultry Science, 40 : 65 – 76.
26. Yasar, S. and Forbes, J.M. (2000). Enzyme supplementation of dry and wet wheat-based feeds for broiler chicken: performance and gut responses. British Journal of Nutrition, 84: 297-307.
27. Yasar, S. and Forbes, J.M. (2001). In vitro estimation of the solubility of dry matter and crude protein of wet feed and dry. Turkish Journal of Veterinary and Animal Sciences, 25: 149-154.