Journal of Animal Science, Vol 72, Issue 11 2980-2991, Copyright © 1994 by American Society of Animal Science

JOURNAL ARTICLE

Kinetics of fiber digestion from in vitro gas production

P. Schofield, R. E. Pitt and A. N. Pell
Department of Animal Science, Cornell University, Ithaca, NY.

In vitro gas production, measured by computer-interfaced pressure sensors, was used to follow the digestion of a crystalline processed cellulose, a bacterial cellulose, and mixtures of these substrates by mixed ruminal bacteria. A first-order, substrate limited model (simple exponential with lag) and two bacterial growth models (logistic, Gompertz) were tested to fit these data. No single pool model gave an optimal fit to all substrates, but dual pool versions of both the logistic and Gompertz models fitted the data extremely well. Derivations of these models in the context of gas production are presented. The dual pool version of the exponential model commonly used to analyze fiber digestion was not able to reproduce the slope variations seen with mixed substrates. A modified dual pool logistic equation, with a single lag value, was selected to model the in vitro digestion of these substrates. The model was able to predict adequately both the input composition and the kinetic parameters for a defined mixture and gave a good fit (r2 > .995) to data from all the single and mixed substrates tested. This model may be useful for interpreting gas accumulation from natural feedstuffs.

This article has been cited by other articles:

				S. X. Tang, G. O. Tayo, Z. L. Tan, Z. H. Sun, L. X. Shen, C. S. Zhou, W. J. Xiao, G. P. Ren, X. F. Han, and S. B. Shen Effects of yeast culture and fibrolytic enzyme supplementation on in vitro fermentation characteristics of low-quality cereal straws J Anim Sci, May 1, 2008; 86(5): 1164 - 1172. [Abstract] [Full Text] [PDF]

				P. Huhtanen, A. Seppala, M. Ots, S. Ahvenjarvi, and M. Rinne In vitro gas production profiles to estimate extent and effective first-order rate of neutral detergent fiber digestion in the rumen J Anim Sci, March 1, 2008; 86(3): 651 - 659. [Abstract] [Full Text] [PDF]

				G. Biagi, A. Piva, M. Moschini, E. Vezzali, and F. X. Roth Performance, intestinal microflora, and wall morphology of weanling pigs fed sodium butyrate J Anim Sci, May 1, 2007; 85(5): 1184 - 1191. [Abstract] [Full Text] [PDF]

				G. Biagi, A. Piva, M. Moschini, E. Vezzali, and F. X. Roth Effect of gluconic acid on piglet growth performance, intestinal microflora, and intestinal wall morphology J Anim Sci, February 1, 2006; 84(2): 370 - 378. [Abstract] [Full Text] [PDF]

				R. Ruiz, L. O. Tedeschi, J. C. Marini, D. G. Fox, A. N. Pell, G. Jarvis, and J. B Russell The Effect of a Ruminal Nitrogen (N) Deficiency in Dairy Cows: Evaluation of the Cornell Net Carbohydrate and Protein System Ruminal N Deficiency Adjustment J Dairy Sci, November 1, 2002; 85(11): 2986 - 2999. [Abstract] [Full Text] [PDF]

				L. R. Lynd, P. J. Weimer, W. H. van Zyl, and I. S. Pretorius Microbial Cellulose Utilization: Fundamentals and Biotechnology Microbiol. Mol. Biol. Rev., September 1, 2002; 66(3): 506 - 577. [Abstract] [Full Text] [PDF]