Precursors of propionate in ruminal fermentation were tested for their ability to decrease methane production by ruminal fluid in vitro. Acrylate and fumarate had the most consistent effects with 50% of the added acids being fermented to propionate and methane production decreasing by between 8 and 14%.
Acrylate and fumarate were evaluated further in Rusitec. Again, both compounds weere fermented to propionate, but the ability of fumarate (44% capture of hydrogen based on the equation 4H(2) +CO2 = CH4 + 2H(2)O and the reduction of fumarate to succinate by 2H) to divert metabolic hydrogen from methane to propionate was almost twice that of acrylate (22% capture of hydrogen).
Four diets comprising grass hay supplemented with furnaric acid at a rate of 0, 20, 40 and 80 g /kg DM were offered at the maintenance plane of nutrition to wether sheep in a 4 x 4 Latin square design. Methane production was measured in open-circuit respiration chambers after 17 d adaptation to the diet. There was no effect of furnaric acid on NDF digestibility. Methane production decreased significantly in a linear response (P<0.01) to increasing inclusion of fumaric acid. The reduction in methane production with inclusion of furnaric acid was 2.9, 4.2 and 12.3% for 20, 40 and 80 g fumaric acid/ kg DM. Hydrogen capture ranged from 65 to 97%.
|Title of host publication||Greenhouse Gases and Animal Agriculture|
|Subtitle of host publication||Proceedings of the 1st International Conference on Greenhouse Gases and Animal Agriculture, Obihiro, Japan, 7-11 November, 2001|
|Place of Publication||Amsterdam|
|Publisher||Elsevier Science B. V.|
|Number of pages||4|
|ISBN (Print)||0-444-51012-5, 978-0444510129|
|Publication status||Published - 2002|
- organic acids
- rumen fermentation