Greenhouse gas emissions from beef feedlot surface materials as affected by diet, moisture, temperature, and time

Authors: Woodbury, Bryan; Gilley, John; Parker, David; Stromer, Bobbi

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2017
Publication Date: 5/1/2018
Citation: Woodbury, B.L., Gilley, J.E., Parker, D.B., Stromer, B.S. 2018. Greenhouse gas emissions from beef feedlot surface materials as affected by diet, moisture, temperature, and time. Transactions of the ASABE. 61(2):571-582. https://doi.org/10.13031/trans.12483.
DOI: https://doi.org/10.13031/trans.12483

Interpretive Summary: A laboratory study was conducted to determine the effects of animal diet, precipitation and temperature on the types and amounts of greenhouse gases emitted from pen surfaces. The purpose of the study was to determine what beef producers can do to reduce the impact of these naturally occurring emissions on the environment. It was determined the amount of these gases emitted were very small when the pen surface was dry. Also, it was found that certain ingredients used to make the animal diet caused some types of greenhouse gases to increase. It was determined from this study that beef producers wanting to limit emissions of greenhouse gases from pen surfaces need to improve or maintain pen drainage systems to speed pen surface drying and consider alternative ingredients for making the ration to be fed to the beef cattle.

Technical Abstract: A laboratory study was conducted to measure the effects of diet, moisture, temperature, and time on greenhouse gas (GHG) emissions from feedlot surface materials (FSM). The FSM were collected from open-lot pens where beef cattle were fed either a dry-rolled corn (DRC) diet containing no wet distillers grains with solubles (WDGS) or a DRC diet containing 35% WDGS. The FSM were collected, air-dried or mixed with 3.0 L of water to represent dry or wet conditions, and then incubated at temperatures of 5°C, 15°C, 25°C, or 35°C. Static flux chambers were used to quantify GHG emissions over a 14-day period. Flux data for each diet × moisture combination were analyzed using repeated measures in time. The largest GHG emissions occurred under wet conditions at temperatures of 25°C and 35°C. Flux values for these conditions typically were significantly greater than measurements obtained on the same day at 5°C and 15°C. Mean emissions under wet conditions for CO2, CH4, and N2O were 35, 121, and 278 times greater, respectively, than emissions from dry FSM. The 0% WDGS diet produced mean CO2 and N2O flux measurements that were 1.8 and 1.5 times greater, respectively, than those obtained for the 35% WDGS diet. The 35% WDGS diet, in contrast, produced a mean CH4 emission rate that was 6 times greater than the 0% WDGS diet. Management for GHG mitigation should include design and/or maintenance of pen drainage to speed drying as well as the use of modified animal diets.