Potenzial und Einschränkungen von pflanzlichen Polyphenolen um Methanemissionen von Wiederkäuern in Graslandbasierten Produktionssystemen zu reduzieren
Biochemie und Biophysik der Pflanzen
Zusammenfassung der Projektergebnisse
Bioactive forages containing tannins have been found to not only reduce CH4 production but also to improve protein utilisation in ruminants and incur anthelmintic effects, benefiting both animal health and productivity. In the first phase of the project, 17 cultivars from eight different forage species were grown under identical conditions and were harvested at different phenological stages. Plant extracts were analysed for their polyphenolic composition and proanthocyanidin (PA) structural characteristics as well as forage yield and quality. Both concentration and composition of these compounds were found vary much higher across different species than the variation within the species. Furthermore, the structural features of PA were found to be more stable across the harvests as well as within the species compared to PA concentration. To assess how these variations would impact the bioactivity of these forages, an in vitro Hohenheim test was conducted on these species to determine their antimethanogenic activity. In general, we found that the CH4 reduction (up to 48%) from tannin containing species (birdsfoot trefoil, big trefoil, sainfoin, sulla and salad burnet) was accompanied with a reduction in gas production (GP, 42%) indicating a negative effect on feed digestibility in rumen. Chicory and plantain produced the lowest CH4 concentration per unit of gas produced among all the forages. The variation in their antimethanogenic activity was found to be linked with the variation in their tannin composition, especially due to tannin concentration and polymer size. However, these factors alone were not able to predict their bioactivity as determined by stepwise regression. Consequently, purified tannin extracts from sulla, birdsfoot trefoil, big trefoil and salad burnet were tested for their antimethanogenic activity, in order to isolate the tannin-effect from the effect of other forage constituents. We found a significant effect of tannin composition on the in vitro ruminal fermentation from different tannin sources. Proanthocyanidin extracts rich in prodelphinidins and high mDP were found to strongly reduce CH4 production (15%) while concomitantly reducing GP (11%) whereas the PA extracts rich in procyanidins reduced CH4 production by 10 % while comparatively incurring lower negative effect on GP (4%). Salad burnet extracts which were rich in hydrolysable tannins produced the lowest CH4 per unit of organic matter digested. The results from this project emphasises the importance of tannin composition especially PA structural features in order to exploit the beneficial effects of tannin containing forages for animal nutrition.
Projektbezogene Publikationen (Auswahl)
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Examining the Variables Leading to Apparent Incongruity between Antimethanogenic Potential of Tannins and Their Observed Effects in Ruminants—A Review. Sustainability, 13(5), 2743.
Verma, Supriya; Taube, Friedhelm & Malisch, Carsten S.
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Large Inter- and Intraspecies Variability of Polyphenols and Proanthocyanidins in Eight Temperate Forage Species Indicates Potential for Their Exploitation as Nutraceuticals. Journal of Agricultural and Food Chemistry, 69(42), 12445-12455.
Verma, Supriya; Salminen, Juha-Pekka; Taube, Friedhelm & Malisch, Carsten S.
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Linking metabolites in eight bioactive forage species to their in vitro methane reduction potential across several cultivars and harvests. Scientific Reports, 12(1).
Verma, Supriya; Wolffram, Siegfried; Salminen, Juha-Pekka; Hasler, Mario; Susenbeth, Andreas; Blank, Ralf; Taube, Friedhelm; Kluß, Christof & Malisch, Carsten Stefan
