| Autor: |
Hixson JL; The Australian Wine Research Institute, P.O. Box 197, Glen Osmond SA 5064, Australia. josh.hixson@awri.com.au., Durmic Z; School of Agriculture and Environment, The University of Western Australia M085, 35 Stirling Hwy, Crawley WA 6009, Australia. zoey.durmic@uwa.edu.au., Vadhanabhuti J; School of Agriculture and Environment, The University of Western Australia M085, 35 Stirling Hwy, Crawley WA 6009, Australia. joy.vadhanabhuti@uwa.edu.au., Vercoe PE; School of Agriculture and Environment, The University of Western Australia M085, 35 Stirling Hwy, Crawley WA 6009, Australia. philip.vercoe@uwa.edu.au.; Institute of Agriculture, The University of Western Australia M085, 35 Stirling Hwy, Crawley WA 6009, Australia. philip.vercoe@uwa.edu.au., Smith PA; The Australian Wine Research Institute, P.O. Box 197, Glen Osmond SA 5064, Australia. paul.smith@wineaustralia.com., Wilkes EN; The Australian Wine Research Institute, P.O. Box 197, Glen Osmond SA 5064, Australia. eric.wilkes@awri.com.au. |
| Abstrakt: |
Ruminants produce large amounts of the greenhouse gas, methane, which can be reduced by supplementing feed with products that contain anti-methanogenic compounds, such as the solid winemaking by-product, grape marc. The aim of this study was to exploit compositional differences in grape marc to better understand the roles of condensed tannin and fatty acids in altering methanogenesis in a ruminant system. Grape marc samples varying in tannin extractability, tannin size and subunit composition, and fatty acid or tannin concentrations were selected and incubated in rumen fluid using an in vitro batch fermentation approach with a concentrate-based control. Four distinct experiments were designed to investigate the effects on overall fermentation and methane production. Generally, fatty acid concentration in grape marc was associated with decreased total gas volumes and volatile fatty acid concentration, whereas increased condensed tannin concentration tended to decrease methane percentage. Smaller, extractable tannin was more effective at reducing methane production, without decreasing overall gas production. In conclusion, fatty acids and tannin concentration, and tannin structure in grape marc play a significant role in the anti-methanogenic effect of this by-product when studied in vitro. These results should be considered when developing strategies to reduce methane in ruminants by feeding grape marc. |
