Livestock production makes up a major share of agriculture sector and the manure it produces significantly contributes to greenhouse gas emissions. One option to lower these emissions significantly is using the manure to produce biogas which is used to generate power. Our model calculations show, that per kWh power from manure-based biogas-about 1.448 kg of CO2 eq. of greenhouse gas (GHG) emission can be avoided due to the improved manure management and the substitution of electricity from the grid under actual German conditions. This form of utilization is supported under the German Renewable Energy Act; however, only the minor share of the manure is processed so far. Thus the question arises as to whether instruments in agricultural policy or instruments in energy policy are better to unlock this remaining potential. The elaborated allocation shows, that both sectors cause a comparable amount of GHG emissions reductions, at around 50% each. However, based on expected developments, the relevance of agriculture-related emissions is slated to increase. This leads to the conclusion that implementing instruments in both agricultural and energy policies would make sense.