Do grass silage based diets lead to higher methane emission than corn silage based diets?


This depends of different factors, because the correlation of feed and emissions is complex. Quite often we see higher GHG emissions for organic milk as the productivity is lower and the grass-based diet triggers higher methane and manure emissions. On the other side for conventional milk production with high protein diets and high dry matter content, we see lower methane and manure emissions and thus lower GHG emissions per kg milk. These feed systems however have very high emissions for the dry matter feed items used.

Therefore, productivity plays an important part, and above factors should help to understand results from the tool. When looking at the numbers, a user should ask “what causes the increase in emissions (feed, methane, manure)? How does the results look when considering total emissions vs. emissions per kg of milk?”