Animal Science Department


Date of this Version



Published in 2009 Nebraska Beef Cattle Report (Lincoln, NE: December, 2008). Copyright © 2008 The Board of Regents of the University of Nebraska.


Individually fed heifers were used to determine the relationship of 3-methyl histidine, purine derivatives, and metabolizableprotein balance to feed efficiency. Heifers were fed finishing dietsthat were either deficient or sufficient in metabolizable protein. Urine samples were collected and analyzed for early, late, and entire feeding period concentrations of 3-methyl histidine, purine derivatives, and creatinine. Results from this study indicated a negative relationship between feed efficiency and metabolizable protein balance, and no relationship between 3-methyl histidine excretion and feed efficiency, suggesting that protein turnover and microbial protein synthesis are not related to feed efficiency