NH3 fraction (%)/Ammonia
The ammonia fraction is a measure of the preservation of the silage and represents the difference between crude protein total and crude protein as a percentage. A high NH3 percentage indicates poor preservation and high protein loss. Silage with high NH3 can also be a sign of clostridia ("harmful microbes"). These also convert protein into NH3. Incidentally, the protein converted into NH3 is still usable, but not as high quality as the crude protein variant.
The ammonia fraction is measured in the following analysis: