a source of non-protein nitrogen ...
Urea contains 46.6 percent nitrogen. Feeder urea is a source of non-protein nitrogen (NPN) with an extremely high crude protein content: 2920 grams of crude protein per kilogram. In ruminants, the urea nitrogen in the rumen is released quickly and completely as ammonium.
We therefore fully add urea to the OE (Non-Protein Protein). Often feed urea is mixed in the concentrate feed to balance the unstable protein balance (OEB).