Development of Urochloa brizantha ethanol and hydroalcoholic extracts as a strategy for methane mitigation

Abstract

Brazil occupies a prominent position in livestock production, however, the significant contribution of ruminants to greenhouse gas (GHG) emissions with a potential effect on climate change have been widely discussed. Despite the valuable ability of the fermentation, the process to transform fibrous foods into high-quality products such as meat and milk, the emission of enteric methane (CH4) is a natural process and can result in up to 12% of energy losses. The growth promoter's inclusion in the diet of ruminants, such as ionophores (for example, sodium monensin), reduces the emission of CH4 and improves the zootechnical performance of the animals. However, several consumer groups and government institutions have adopted the ban on synthetic drugs to keep the product free of any residues. Due to these restrictions, alternatives have been studied and plants represent an important potential for study, as they have several secondary metabolites (for example, saponins, tannins, and essential oils) with the ability to manipulate ruminal fermentation favorably. Urochloa brizantha is a tropical grass widely used as pasture in Brazil, studies have already been carried out addressing its photosensitization effect in animals due to saponin presence. However, research on secondary compost extraction from this grass and its effects on rumen fermentation has not yet been explored. Therefore, the present proposal aims to produce ethanolic and hydroalcoholic Urochloa brizantha extracts and to evaluate the effect of the addition of the extracts on the production of in vitro and in vivo gases - added on lambs' feedings as a strategy to mitigate GHG emissions. It is expected that the addition of extracts will modulate ruminal fermentation to reduce gas production and improve the SCFA profile, without generating environmental impact. The originality of the proposal lies in the evaluation of a plant widely exploited in Brazil in ruminant production, whose concentrated extract can have promising results for the national livestock chain sustainability. (AU)