Methane index
Definition
The Methane index indicates the predicted methane emissions from the silage when digested by cows. It provides insight into the greenhouse gas emissions associated with that forage and compares it to seasonal references.
Importance
Methane (CH₄) is a potent greenhouse gas mainly produced by ruminants during digestion. Around 75% of methane emissions from livestock originate from enteric fermentation. Reducing these emissions is key to lowering agriculture’s environmental impact.
In a typical dairy ration, 70% of methane emissions come from forage. Methane Indicators Absolute methane emission: g CH₄ per kg dry matter
Methane index: Normalised to correct for seasonal differences, allowing silages from different seasons or years to be compared
Interpreting the Methane index
>100: More methane than expected for the season
<100: Less methane than expected
Target value
Methane Index <100
