Evaluation of Models to Predict Dry Matter Intake of Forage Based Diets

Authors

Aksel Wiseman, University of Nebraska–Lincoln
Andrea K. Watson, University of Nebraska–Lincoln
Rick Stock, University of Nebraska–Lincoln
Terry Klopfenstein, University of Nebraska–Lincoln

Date of this Version

2022

Citation

2022 Nebraska Beef Cattle Report

UNL Beef, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln

Abstract

Dry matter intake (DMI) data from growing cattle experiments at the Eastern Nebraska Research and Extension Center were summarized in order to evaluate the accuracy of model predicted DMI. Cattle were fed individually (n = 78) or in pens (n = 15) and predicted DMI using the Beef Cattle Nutrient Requirements Model (BCNRM, 2016) was compared to observed DMI. The model over predicted DMI when total digestible nutrients (TDN) was less than 64%, under predicted DMI when dietary TDN was greater than 64%, and had a low accuracy, explaining less than 22% of the variation in DMI. An equation to predict DMI was developed using dietary neutral detergent fiber (NDF), energy (NEm), and calf shrunk body weight. The inclusion of dietary NDF concentration improved the prediction precision of DMI for growing cattle consuming low-energy, forage-based diets. Intake may be limited due to rumen fill as well as decreased passage rate from the high NDF concentration of the diets. Including the additional variable of dietary NDF could allow for more precise predictions of DMI and animal performance resulting in more accurate dietary formulations.