Net Energy Evaluation for Beef Cattle Rations Compared with Evaluation by Metabolizable Energy Measurements

Publisher Website
Google Scholar
Abstract
Six finishing beef cattle rations differing with respect to stilbestrol additions and either the amount of corn grain present or the moisture content of whole-plant corn silage were each evaluated by two calorimetric techniques. One technique, involving metabolizable energy measurements, is used by the British Agricultural Research Council (A.R.C., 1965), and the other technique, involving net energy measurements, is used by the American National Research Council (N.R.C., 1969) in evaluating beef cattle rations. Our results obtained with the six rations employing the two techniques simultaneously gave values intermediate between the N.R.C. and A.R.C. predicted values. The results further suggested that, in feedlot cattle, the values obtained by one technique could better be transposed into values of the other technique on the basis that 80% concentrate rations, when fed ad libitum, have an efficiency of conversion of metabolizable energy to net energy for maintenance of 75% and to net energy for live weight gain of 45%. Similarly, finishing rations with 40% concentrates, when fed ad libitum, have an efficiency of conversion of metabolizable energy to net energy for maintenance of 65% and to net energy for live weight gain of 47%. The data demonstrated that stilbestrol produced slightly leaner carcasses such that net energy requirements per unit of live weight gain in cattle were significantly improved without appreciably altering efficiency of conversion of ration calories into deposited carcass calories.

This publication has 0 references indexed in Scilit: