DOI: 10.5061/dryad.qnk98sfsn
title: Evaluation of models of enteric methane emissions in finishing steers

description: Accurate estimation of enteric CH4 emissions (i.e., MJ or g of CH4/ day)
 in the ruminant sector is necessary for properly determining GHG emissions
 and developing measuring, reporting, and verification programs. However,
 measuring enteric CH4 emissions under commercial conditions presents
 challenges due to technical and economic constraints. Thus, using
 prediction models allows for estimating individual enteric CH4 emissions
 according to animal and dietary characteristics. When evaluated in
 independent datasets, there is limited information regarding the accuracy
 and precision of the reported equations to predict enteric CH4 emissions
 in steers fed a finishing diet. This study evaluated the predictive
 performance of various reported equations for estimating enteric CH4
 production in finishing steers. Data used to assess the prediction
 equations came from 446 steers from five experiments during the finishing
 phase. Gas flux, nutrient consumption, and animal growth performance were
 evaluated in each experiment. Seventy-two equations were compared based on
 the mean square prediction error (MSPE), the decomposition of the root
 MSPE (RMSPE), and the concordance correlation coefficient (CCC).
 Prediction equations for estimating enteric CH4 emissions showed lower
 sensitivity with RMSPE (as a percentage of the observed mean) ranging from
 17.79 to 99.21 and CCC ranging from -0.07 to 0.21. The decomposition of
 the RMSPE showed mean bias (as a percentage of the RMSPE) ranging from
 0.14 to 94.87 and slope bias (as a percentage of the RMSPE) ranging from 0
 to 25.24. In addition, 49 equations underpredicted (ranging from 0.6 to
 50.1%) and 23 overpredicted (ranging from 3.7 to 96.1%) enteric CH4
 emissions. The prediction of enteric CH4 production showed greater CCC and
 lower MSPE when the intake of dry matter and ether extract were included
 as predictors. These results suggest a limited ability to predict enteric
 CH4 by steers during the finishing phase. Further efforts are required to
 generate sensitive models to accurately predict enteric CH4 emissions in
 finishing steers.
description: # Model evaluation of predicting enteric methane emissions in finishing
 steers
 [https://doi.org/10.5061/dryad.qnk98sfsn](https://doi.org/10.5061/dryad.qnk98sfsn) ## Description of the data and file structure Data are from 5 independent experiments with *Bos taurus* cattle fed an energy dense finishing diet. Emissions data were collected via Greenfeed units (C-Lock Inc, Rapid City, SD). Feed intake was collected from Smartfeed units (C-Lock Inc., Rapid City, SD). Feed composition data were determined via wet chemistry by Dairy One (Ithaca, NY).  ### File: Sup_T1_Met_Pre_Rev.pdf **Description:** Table with models and references.  ### File: Fig_1_Met_pred.tif **Description:** Figure with comparing Concordance Correlation Coefficient (CCC) and Root Mean Square Prediction Error (RMSPE) of evaluated models. ### File: Fig_2_Met_pred.tiff **Description:** Figure comparing proportion of evaluated models that under and over predicted methane emissions.  #### File: Database_09-11-2025.csv **Description:** Independent dataset used for model evaluation ##### Variables * Project: project code for each of the 5 independent experiments in the dataset * Animal: unique animal id within the dataset * Breed: breed type of the animal * ADG_Fin: average daily gain in kg * SMBW_Fin: Shrunk mid body weight in kg * DMI_Fin: dry matter intake in kg * CO2_Fin: carbon dioxide emissions in g per day * CH4_Fin: methane emissions in g per day * CH4_MJ_Fin: enteric methane emissions in MJ per day * O2_Fin: oxygen consumption in g per day * CP_%: crude protein percentage in the diet * NDF_%: neutral detergent fiber percentage in the diet * Hem_%: hemicellulose percentage in the diet * ADF_%: acid detergent fiber percentage in the diet * Lig_%: Lignin percentage in the diet * Cel_%: Cellulose percentage in the diet * NFC_%: Non-fiber carbohydrates percentage in the diet * Sta_%: Starch percentage in the diet * EE_%: Ether extract percentage in the diet * Ash_%: Ash percentage in the diet * Forage_%: Forage percentage in the diet * TDN_%: total digestible nutrients percentage in the diet * NEm_Mcalkg: net energy for maintenance density in the diet in Mcal per kg of dry matter * NEg_Mcalkg: net energy for gain density in the diet in Mcal per kg of dry matter * GE_Mcalkg: gross energy density in the diet in Mcal per kg of dry matter #### File: metadata.docx **Description:** A copy of this README ## Code/software R code script and needed packages are provided in **Model_evaluation_syntaxis_animal.txt.**  ## Version changes 16-sept-2025: updated data in **Database_09-11-2025.csv** for data from project 2024A, due to a GreenFeed data processing error by C-Lock, Inc.  24-feb-2026: separate metadata file metadata.docx with README information added. In variable list, CH4_MJ_Fin variable description has been added