Effect of nitrogen-reduced diet on NH3 and N2O emissions of dairy cows
The NH3 and N2O emissions from two parallel pasture-based feeding systems with dairy cattle were measured. In one system cows were fed exclusively on pasture grass, in the other system 25% maize silage was supplemented.
This resulted in a reduced protein-to-energy ratio in the M diet, and correspondingly the amount of excreted nitrogen was decreased by about 19%. The obtained results showed that the default N2O emission factor currently used in the Swiss greenhouse gas inventory is probably too high. The study demonstrated that protein-reduced feed can contribute to a reduction in NH3 and N2O emissions on the pasture.