Effect of Different Silages for TMR on In vitro Rumen Simulative Fermentation

  • Received : 2012.11.07
  • Accepted : 2012.12.03
  • Published : 2012.12.31


In this study, the in vitro fermentation parameters of whole crop barley (WCBS-TMR) and Italian ryegrass (IRGS-TMR) silage total mixed rations were compared. A rice straw based diet (RSBD), which was a mixture of rice straw and concentrate (60:40), was used as the control. The feeds were incubated in buffered rumen fluid for 3, 6, 9, 12, 24, 48 and 72 hours at $39^{\circ}C$. At the end of each incubation period the following parameters were determined, total gas, pH, ammonia nitrogen ($NH_3$-N), volatile fatty acids (VFA) and then the acetate to propionate ratio (A/P) was calculated. The dietary treatments did not affect (p>0.05) the overall production of $NH_3$-N, gas, total VFA and all the individual VFA, with the exception of n-butyrate (p<0.001). The treatment diets significantly affected the A/P ratio (p<0.01). The control diet resulted in the lowest A/P ratios, followed by WCBS-TMR and lastly IRGS-TMR had the highest ratios. Gas production was not different between treatments, suggesting a probable similar level of digestibility when treatments are fed to animals. It can therefore be concluded from the present study that WCBS and IRGS are of almost an equivalent nutritional value when incubated in a TMR form. WCBS-TMR however resulted in lower A/P ratios than IRGS-TMR, which is indicative of a more energy efficient diet.


Grant : Cooperative Research Program for Agriculture Science & Technology Development

Supported by : Rural Development Administration


  1. Chaney, A.L. and Marbach, E.P. 1962. Modified reagents for the determination of urea and ammonia. Clinical Chemistry. 8:130-132.
  2. Erwin, E.S., Marco, J. and Emery, E.M. 1961. Volatile fatty acid analysis of blood and rumen fluid by gas chromatography. Journal of Dairy Science. 44:1768-1771.
  3. Gao, L.J., Yang, H.Y., Huang, X.F. Ishii, M.Y., Igarashi, Y. and Cui, Z. 2008. Rice straw fermentation using lactic acid bacteria. Bioresource Technology. 99:2742-2748.
  4. Mbiriri, D.T., Oh, S.J., Lee, A.R., Chae, J.I., Choi, C.W. and Choi, N.J. 2012. In vitro rumen fermentation patterns of environmental friendly whole crop barley, Italian ryegrass and rice straw silages. Korean Journal of Organic Agriculture. 20:221-230.
  5. Menke, K.H., Raab, L., Salewski, A., Steingass, H., Fritz, D. and Schneider, W. 1979. The estimation of digestibility and metabolisable energy content of ruminant feeding-stuffs from the gas production when they are incubated with rumen liquor in vitro. Journal of Agricultural Science (Cambridge) 93:217-222.
  6. Perdok, H. and Leng, R.A. 1989. Rumen ammonia requirements for the efficient digestion and intake of straw by cattle. In: The role of protozoa and fungi in ruminant digestion (Ed. J. V. Nolan and R. A. Leng), Penambul Books, Armidale, Australia.
  7. Tilley, J.M.A. and Terry, R.A. 1963. A two stage technique for the in vitro digestion of forage crops. Journal of the British Grassland Society. 18:104-111.
  8. Troelsen, J.M. and Donna, H.J. 1966. Ruminant digestion in vitro as affected by inoculums donor collection day, and fermentation time. Canadian Journal of Animal Science. 46:149-156.
  9. Van Saun, R.J. 2007. Forage testing: How to translate numbers into actions. In: Proceedings of 2006 Mid-Atlantic States Conference for Bovine Practitioners, Fredrick, Maryland, March 30-31, 2006, pp. 13.
  10. Wolin, M.J. 1960. A theroretical rumen ferment- ion balance. Journal of Dairy Science. 3:1452- 1459.