Effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro disappearance and gas production for feedlot cattle

  • Received : 2016.05.03
  • Accepted : 2016.08.06
  • Published : 2017.04.01


Objective: The effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro dry matter (DM) disappearance (DMD), gas production and fermentation pH were investigated for feedlot cattle. Methods: Rumen fluid from four fistulated feedlot cattle fed a diet of 860 dry-rolled barley grain, 90 maize silage and 50 supplement g/kg DM was used as inoculum in 3 batch culture in vitro studies. In Experiment 1, dry-rolled barley and barley ground through a 1-, 2-, or 4-mm screen were used to obtain four substrates differing in particle size. In Experiment 2, cellulase enzyme (ENZ) from Acremonium cellulolyticus Y-94 was added to dry-rolled and ground barley (2-mm) at 0, 0.1, 0.5, 1, and 2 mg/g, while Experiment 3 examined the interactions between microwaving (0, 30, and 60 s microwaving) and ENZ addition (0, 1, and 2 mg/g) using dry-rolled barley and 2-mm ground barley. Results: In Experiment 1, decreasing particle size increased DMD and gas production, and decreased fermentation pH (p<0.01). The DMD (g/kg DM) of the dry-rolled barley after 24 h incubation was considerably lower (p<0.05) than that of the ground barley (119.1 dry-rolled barley versus 284.8 for 4-mm, 341.7 for 2-mm; and 358.6 for 1-mm). In Experiment 2, addition of ENZ to dry-rolled barley increased DMD (p<0.01) and tended to increase (p = 0.09) gas production and decreased (p<0.01) fermentation pH, but these variables were not affected by ENZ addition to ground barley. In Experiment 3, there were no interactions between microwaving and ENZ addition after microwaving for any of the variables. Microwaving had minimal effects (except decreased fermentation pH), but consistent with Experiment 2, ENZ addition increased (p<0.01) DMD and gas production, and decreased (p<0.05) fermentation pH of dry-rolled barley, but not ground barley. Conclusion: We conclude that cellulase enzymes can be used to increase the rumen disappearance of barley grain when it is coarsely processed as in the case of dry-rolled barley. However, microwaving of barley grain offered no further improvements in ruminal fermentation of barley grain.


  1. United States Department of Agriculture. World agricultural production. [Internet] Foreign agricultural service, United states department of agriculture; 2015 [cited 2015 June 16]. Available from:
  2. Dehghan-banadaky M, Corbett R, Oba M. Effects of barley grain processing on productivity of cattle. Anim Feed Sci Technol 2007;137:1-24.
  3. Leek ABG, Callan JJ, Reilly P, Beattie VE, O'Doherty JV. Apparent component digestibility and manure ammonia emission in finishing pigs fed diets based on barley, maize or wheat prepared without or with exogenous non-starch polysaccharide enzymes. Anim Feed Sci Technol 2007;135:86-99.
  4. Benabdeljelil K, Arbaoui MI. Effects of enzyme supplementation of barley-based diets on hen performance and egg quality. Anim Feed Sci Technol 1994;48:325-34.
  5. Fuente JM, Perez de ayala P, Cillamide MJ. Effect of dietary enzyme on the metabolizable energy of diets with increasing levels of barley fed to broilers at different ages. Anim Feed Sci Technol 1995;56:45-53.
  6. Rode LM, Yang WZ, Beauchemin KA. Fibrolytic enzyme supplements for dairy cows in early lactation. J Dairy Sci 1999;82:2121-6.
  7. Koenig KM, Beauchemin KA, Rode LM. Effect of grain processing and silage on microbial protein synthesis and nutrient digestibility in beef cattle fed barley-based diets. J Anim Sci 2003;81:1057-67.
  8. Zhao YL, Yan SM, He ZX, et al. Effects of volume weight, processing method and processing index of barley grain on in situ digestibility of dry matter and starch in beef heifers. Anim Feed Sci Technol 2015;199:93-103.
  9. McAllister TA, Rode LM, Major DJ, Cheng KJ, Buchanan-Smith JG. Effect of ruminal microbial colonization on cereal grain digestion. Can J Anim Sci 1990;70:571-9.
  10. Beauchemin KA, Yang WZ, Rode LM. Effects of barley grain processing on the site and extent of digestion of beef feedlot finishing diets. J Anim Sci 2001;79:1925-36.
  11. Krause M, Beauchemin KA, Rode LM, Farr BI, Norgaard P. Fibrolytic enzyme treatment of barley grain and source of forage in high-grain diets fed to growing cattle. J Anim Sci 1998;76:2912-20.
  12. Sadeghi AA, Shawrang P. Effect of microwave irradiation on ruminal dry matter, protein and starch degradation characteristics of barley grain. Anim Feed Sci Technol 2008;141:184-94.
  13. Fujii T, Fang X, Inoue H, Murakami K, Sawayama S. Enzymatic hydrolyzing performance of Acremonium cellulolyticus and Trichoderma ressi against three lignocellulosic materials. Biotechnol Biofuels 2009;2:24-31.
  14. Anele UY, Refat B, Swift ML, et al. Effect of bulk density, precision processing and processing index on in vitro ruminal fermentation of dry-rolled barley grain. Anim Feed Sci Technol 2014;195:28-37.
  15. Goering HK, Van Soest PJ. Forage fiber analysis (apparatus, reagents, procedures and some applications), Agricultural handbook No. 379, Washington, DC: ARS-USDA, 1970.
  16. Mauricio RM, Mould FL, Dhanoa MS, et al. A semi-automated in vitro gas production technique for ruminant feedstuff evaluation. Anim Feed Sci Technol 1999;79:321-30.
  17. AOAC. Official methods of analysis, 16th ed. Association of Official Analytical Chemists, Arlington, VA: AOAC International; 1995.
  18. Van Soest PJ, Robertson JB, Lewis BA. Symposium: carbohydrate methodology, metabolism and nutrition. J Dairy Sci 1991;74:3583-97.
  19. Getachew G, Crovetto GM, Fondevila M, et al. Laboratory variation of 24 h in vitro gas production and estimated metabolizable energy values of ruminant feeds. Anim Feed Sci Technol 2002;102:169-80.
  20. Anele UY, Refat B, Swift ML, et al. In vitro fermentation ruminal of ground and dry rolled barley grain differing in starch content. Anim Feed Sci Technol 2015;203:88-94.
  21. Yang WZ, Beauchemin KA, Rode LM. A comparison of methods of adding fibrolytic enzymes to lactating cow diets. J Dairy Sci 2000;83:2512-20.
  22. Zhu Y, Nishino N, Xusheng G. Chemical changes during ensilage and in sacco degradation of two tropical grasses: rhodesgrass and guineagrass treated with cell wall-degrading enzymes. Asian-Australas J Anim Sci 2011;24:214-21.
  23. Yamanobe T, Mitsuishi Y, Takasaki Y. Isolation of a cellulolytic enzyme producing microorganism, culture conditions and some properties of the enzymes. Agric Biol Chem 1987;51:65-74.
  24. Colombatto D, Hervas G, Yang WZ, Beauchemin KA. Effects of enzyme supplementation of a total mixed ration on microbial fermentation in continuous culture, maintained at high and low pH. J Anim Sci 2003;81:2617-27.
  25. Yin Y, Walker CE. A quality comparison of breads baked by conventional versus nonconventional ovens: a review. J Sci Food Agric 1995;67:283-91.

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