Login

A theoretical comparison between two ruminal electron sinks.

Emilio M. Ungerfeld

CONICYT Regional R10C1002, Centro de Investigación y Desarrollo CIEN Austral, Universidad Austral de Chile, Puerto Montt, Chile.

Frontiers in Microbiology 4, 319, October 2013.

Dihydrogen accumulation resulting from methanogenesis inhibition in the rumen is an energy loss and can inhibit fermentation. The objective of this analysis was to compare the energetic and nutritional consequences of incorporating H2 into reductive acetogenesis or additional propionate production beyond the acetate to propionate shift occurring along with methanogenesis inhibition. Stoichiometric consequences were calculated for a simulated fermentation example. Possible nutritional consequences are discussed. Incorporating H2 into reductive acetogenesis or additional propionate production resulted in equal heat of combustion output in volatile fatty acids (VFA). Incorporation of H2 into reductive acetogenesis could result in moderate decrease in ruminal pH, although whole-animal buffering mechanisms make pH response difficult to predict. Research would be needed to compare the microbial protein production output. There could be post-absorptive implications due to differences in VFA profile. Electron incorporation into reductive acetogenesis could favor energy partition toward milk, but increase risk of ketosis in high-producing dairy cows on ketogenic diets. Greater propionate production could favor milk protein production, but may be less desirable in animals whose intake is metabolically constrained, like feedlot steers. Because of the different nutritional implications, and because practical solutions to incorporate H2 into either pathway are not yet available, it is recommended to research both alternatives. 

 

 

 

 

Back to Publications

Latest News View All

  • Joint LRG Networks workshop

    Joint LRG Networks workshop  Research networks of the GRA Livestock Research Group (LRG) held a joint workshop at the University of Reading, United Kingdom, on... Read more

  • Update - Ruminomics Regional Workshop

    Ruminomics Regional Workshop. Warsaw, Poland. 1-2 September 2015.  The next version of the programme in support of the Ruminomics regional workshop in Warsaw,... Read more

Publications View All

ForumView All

 Co-ordinated by

AgR Corp RGB.jpg

 Funding provided by

All-of-govt_NZ_Gov.jpg

 In support of the

LRG logo.jpg

part of the

Alliance Lockup-white-temp_2.JPG