Impact of Urea on Corn Silage Growing Cattle Diets

Authors

Tyler J. Spore, University of Nebraska - Lincoln
Hannah C. Wilson, University of Nebraska - Lincoln
Nolan R. Meier, University of Nebraska - Lincoln
Galen E. Erickson, University of Nebraska - LincolnFollow
James C. MacDonald, University of Nebraska - LincolnFollow
Terry J. Klopfenstein, University of Nebraska - Lincoln
Andrea K. Watson, 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

Two experiments were conducted to evaluate the effects of increasing urea in a corn silage growing cattle diet and ensiling time impact on rumen undegradable protein content of corn silage. Four treatments (urea inclusion at 0, 0.5, 1, and 1.5% of diet dry matter) were evaluated in diets containing 95% corn silage using 10 ruminally and duodenally cannulated heifers. Corn silage was sampled 5 times (every 32 days) to determine rumen undegradable protein content. Intake and total tract digestibility of dry matter, organic matter, and neutral detergent fiber all increased linearly with increasing inclusion of urea in the diet. Measured microbial crude protein synthesis was greatest for the 0.5 and 1% urea diets, averaging 15% of TDN. As ensiling time increased, rumen undegradable protein content of the corn silage decreased from 32% of crude protein on the day of corn silage harvest to 17% after 160 days. This was primarily driven by changes in the corn grain in the first 30 days of ensiling as the forage component of the corn silage had little change across time.