A dynamic mechanistic model of lactic acid metabolism in the rumen

Mills, J. A. N., Crompton, L. A., Ellis, J. L., Dijkstra, J., Bannink, A., Hook, S., Benchaar, C. and France, J. (2014) A dynamic mechanistic model of lactic acid metabolism in the rumen. Journal of Dairy Science, 97 (4). pp. 2398-2414. ISSN 0022-0302 doi: 10.3168/jds.2013-7582

Abstract/Summary

Current feed evaluation systems for ruminants are too imprecise to describe diets in terms of their acidosis risk. The dynamic mechanistic model described herein arises from the integration of a lactic acid (La) metabolism module into an extant model of whole-rumen function. The model was evaluated using published data from cows and sheep fed a range of diets or infused with various doses of La. The model performed well in simulating peak rumen La concentrations (coefficient of determination = 0.96; root mean square prediction error = 16.96% of observed mean), although frequency of sampling for the published data prevented a comprehensive comparison of prediction of time to peak La accumulation. The model showed a tendency for increased La accumulation following feeding of diets rich in nonstructural carbohydrates, although less-soluble starch sources such as corn tended to limit rumen La concentration. Simulated La absorption from the rumen remained low throughout the feeding cycle. The competition between bacteria and protozoa for rumen La suggests a variable contribution of protozoa to total La utilization. However, the model was unable to simulate the effects of defaunation on rumen La metabolism, indicating a need for a more detailed description of protozoal metabolism. The model could form the basis of a feed evaluation system with regard to rumen La metabolism.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/39200
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Animal Sciences > Animal, Dairy and Food Chain Sciences (ADFCS)- DO NOT USE
Uncontrolled Keywords	lactic acid; rumen; mechanistic model
Publisher	Elsevier
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