Animal Science, Department of


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.


A maturity index (MI) was developed using data from Gudmundsen Sandhills Laboratory to predict a heifer’s optimal size for breeding. It was developed from observable information such as age, feeding regime, pre-breeding, birth and dam weights. The MI was the most precise predictor of actual percentage of mature weight versus using estimates developed from the herd’s estimated average weight or the dam’s mature weight. The MI also was a more accurate predictor of first pregnancy than the typically applied measure.