Although New York researchers have suggested 35 to 40 percent of the crude protein as UIP (undegraded intake protein), little to no data has ever shown the need for rumen undegradable protein for heifers. Feed standard feedstuffs and they often run 25-25% UIP. Corn UIP will be low in lysine, so make sure the ration has a favorable amino acid profile by including soybean meal etc. We recommend 16-18% crude protein up six months of age.
Mike Hutjens, Extension Dairy Specialist, University of Illinois - Illini DairyNET
Arlyn Heinrichs, Dairy Extension, Penn State University.
Hugh Chester-Jones, Dairy and Beef Specialist, U of MN.
