| Popis: |
Plant secondary metabolites (PSMs) can potentially reduce ruminal methane formation. However, due to the variability of the molecular structures, it is not yet clear what causes their anti-methanogenic effect. In an in vitro system simulating rumen fermentation, we have tested the impact of eight compounds with distinct chemical characteristics (gallic and salicylic acids, tannic acid, catechin, epicatechin, quercetin, rutin, and salicin) when added to a basal feed (maize silage) at a concentration of 12% of the feed dry matter. After 48 hours of incubation in buffered rumen fluid, methane production was significantly lowered by quercetin (43%), tannic acid (39%) and salicylic acid (34%) without changes on total volatile fatty acid production during fermentation as compared to control, maize silage alone. No other PSMs reduced methane formation as compared to control but induced significant differences on total volatile fatty acid production. Our results indicate the importance of distinct molecular structures of PSMs and chemical characteristics for methane reducing properties and volatile fatty acid formation during rumen fermentation, which were related to lipophilicity, the presence of double bound and carbonyl group, sugar moieties as well as polymerization. Systematic screening studies to establish the structure-function relationship between PSMs and methane reduction are warranted. |
