Chemical Composition, Ruminal Dry Matter, Crude Protein andCell Wall Degradation Kinetics of Pasture Forages Dominant in the West Provinces of Iran


1 Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Karaj, Iran

2 Department of Animal Science, Science and Research Branch, Islamic Azad University, Tehran, Iran


The objectives of this study were to determine and compare the chemical composition and ruminal degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of ten pasture forage species dominant in the west provinces of Iran. Duplicate nylon bags of pasture samples were suspended in the rumen of four wethers for up to 96 h. The chemical composition of forages varied from 54 to 212 g/kg DM for CP, 239 to 638 g/kg DM for NDF, 190 to 378 g/kg DM for ADF and 60 to 108 g/kg DM for ash. The effective DM degradability at rumen outflow rate of 0.05/h was different (P<0.05) between forages and varied from 307 g/kg for Festuca ovina to 679 g/kg for Prangus ferulacea. The lowest CP degradability was for Festuca ovina (402 g/kg) and the highest for Bromus tomentellus (760 g/kg). The lowest NDF and the highest ADF degradability were for Hordeum bulbosum and Prangus ferulacea, respectively. The results of this study showed that the rate and extent of ruminal CP and cell wall degradation were different among forages, therefore must be considered as a main parameter in ration formulation of grazing ruminants.


Allen M.S. and Mertens D.R. (1988). Evaluating constraints of fibre digestion by rumen microbes. J. Nutr. 118, 261-270.
Arzani H., Torkan J., Jafari M., Jalili A. and Nikkhah A. (2001). Effects of phenological stages and ecological factors on forage quality of some range species. Iranian J. Agric. Sci. 32, 385-397.
AOAC. (1995). Official Methods of Analysis. 16th Ed. Association of Official Analytical Chemists, Arlington, VA, USA.
Aydin R., Kamalak A. and Canbolat O. (2007). Effect of maturity on the potential nutritive value of burr medic (Medicago polymorha) hay. J. Biologic. Sci. 7, 300-304.
Dongmei X., Wanapat M., Weidong D., Tianbao H., Zhi-fang Y. and Huaming M. (2008). Comparison of Gayal (Bos frontalis) and Yunnan yellow cattle (Bos taurus): in vitro dry matter digestibility and gas production for a range of forages. Asian-australas. J. Anim. Sci. 20,1208-1214.
Evitayani L., Warly A., Fariani T. and Fujihara T. (2004). Study on nutritive value of tropical forages in North Sumatra, Indonesia. Asian-australas. J. Anim. Sci. 17, 1518-1523.
Fujihara T., Osuga I.M., Abdulrazak S.A. and Ichinohe T. (2005). Chemical composition, degradation characteristics and effect of tannin on digestibility of some browse species from Kenya harvested during the wet season. Asian-australas. J. Anim. Sci. 18, 54-60. 
Kamalak A., Canbolat O., Gurbuz Y., Erol A. and Ozay O. (2005a). Effect of maturity stage on the chemical composition, in vitro and in situ degradation of tumbleweed hay (Gundelia tuonefortii). Small Rumin. Res. 58, 149-156.
Kamalak A., Canbolat O., Gurbuz Y., Ozkan O.O. and Kiz-ilsimsek M. (2005b). Determination of nutritive value of wild mustard, Sinapsis arvensis, harvested at different maturity stages using in situ and in vitro measurements. Asian-australas. J. Anim. Sci. 18,1249-1254.
Karabulut A., Canbolat O., Kalkan H., Gurbuzol F., Sucu E. and Filya I. (2007). Comparison of in vitro gas production, metabolizable energy, organic matter digestibility and microbial protein production of some legume hays. Asian-australas. J. Anim. Sci. 20,517-523.
Ørskov E.R. and McDonald I. (1979). The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. J. Agric. Sci. 92, 499-503.
SAS Institute. (1996). SAS®/STAT Software, Release 6.11. SAS Institute, Inc., Cary, NC.
Steel R.G.D. and Torrie J.H. (1980). Principles and Procedures of Statistics: A Biometrical Approach. McGraw Hill, New York, USA.
Van Soest P.J. (1994). Nutritional Ecology of the Ruminant. Cornell University Press, Ithaca, USA.
Van Soest P.J., Mertens D.R. and Deinum B. (1978). Preharvest factors influencing quality of conserved forage. J. Anim. Sci. 47, 712-720.
Van Soest P.J., Robertson J.B. and Lewis B.A. (1991). Methods for dietary fiber, neutral detergent fiber and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74, 3583-3597.
  • Receive Date: 21 December 2011
  • Revise Date: 22 February 2012
  • Accept Date: 01 March 2012
  • First Publish Date: 01 June 2013