We would use the following strategies:
1. Low milk protein test for the breed relative to milk fat content (for U.S. Holsteins, the ratio of true milk protein to milk fat is 0.81% or 3.0/3.7).
2. Evaluate forage and grain energy sources for potential amino acid shortage (for example, 75% corn silage as forage source, shelled corn, and corn distillers grain as the main protein source would lead to a potential lysine shortage).
3. Evaluate the ration using CPM or Dairy NRC 2001 amino acid model to calculate estimates of amino acid sufficiency.
4. Manure scores would not be useful.
Mike Hutjens, Extension Dairy Specialist, University of Illinois - Illini DairyNET
