Nutritional Interventions to Reduce Methane Emissions in Ruminants

Abstract

Methane is the single largest source of anthropogenic greenhouse gases produced in ruminants. As global warming is a main concern, the interest in mitigation strategies for ruminant derived methane has strongly increased over the last years. Methane is a natural by-product of anaerobic microbial (bacteria, archaea, protozoa, and fungi) fermentation of carbohydrates and, to a lesser extent, amino acids in the rumen. This gaseous compound is the most prominent hydrogen sink product synthesized in the rumen. It is formed by the archaea, the so-called methanogens, which utilize excessive ruminal hydrogen. Different nutritional strategies to reduce methane production in ruminants have been investigated such as dietary manipulations, plant extracts, lipids and lipid by-products, plant secondary metabolites, flavonoids, phenolic acid, statins, prebiotics, probiotics, etc. With the range of technical options suggested above, it is possible to develop best nutritional strategies to reduce the ill effects of livestock on global warming. These nutritional strategies seem to be the most developed means in mitigating methane from enteric fermentation in ruminants and some are ready to be applied in the field at the moment.