A global dataset of enteric methane mitigation experiments with lactating and non-lactating dairy cows conducted from 1963 to 2022

A dataset of descriptive information was compiled from 213 peer-reviewed scientific publications that focused on dairy cow experiments and measured enteric methane emissions. This dataset was primarily based on the bibliography used by Arndt et al. (2022), with the addition of studies conducted from 2019 to 2022. The articles were identified for inclusion in the dataset using the “Web of Science Core Collection” database, using various combinations of search terms related to methane, dairy, cattle, rumen, ruminant, energy balance, energy metabolism, energy partitioning, and enteric emissions. For inclusion in the dataset, studies had to be written in English and provide information on enteric methane emission, as well as report feed dry matter intake along with measures of variance. Both continuous and crossover design studies were included, resulting in a comprehensive dataset with 797 records (rows) and 162 variables (columns). The variables cover various aspects such as publication information, experimental design, animal description, methane measurement method, and diet nutrient composition. Additionally, when available, the dataset includes treatment means and measures of variance for feed dry matter intake, rumen fermentation parameters, nutrient digestibility, nitrogen excretion, milk yield, milk components, as well as enteric methane, carbon dioxide, and hydrogen emissions. Researchers can use this dataset to assess the effectiveness of different enteric methane mitigation strategies and their impact on milk yield and other essential dairy cow nutrition and performance variables. Furthermore, it offers the opportunity to explore potential interactions between nutrients and feed additives.

nitrogen excretion, milk yield, milk components, as well as enteric methane, carbon dioxide, and hydrogen emissions. Researchers can use this dataset to assess the effectiveness of different enteric methane mitigation strategies and their impact on milk yield and other essential dairy cow nutrition and performance variables. Furthermore, it offers the opportunity to explore potential interactions between nutrients and feed additives.  Table   Subject Animal Science Specific subject area Dairy cow enteric methane emissions, milk and milk components, nutrient digestibility, and rumen parameters associated with consumed nutrients and feed additives. Type of data Table  How the data were acquired Data was acquired from scientific publications. The bibliography used by Arndt et al. [1] (1963 to 2018) was supplemented with a literature search to cover the period between 2019 and 2022. The literature search on the Web of Science Core Collection database used the term "methane" in combination with "dairy", "cattle", "rumen", or "ruminant". Additionally, the search term "rumen" was used in combination with "energy balance", "energy metabolism", or "energy partitioning". A final search was conducted with the terms "enteric" and "dairy".

Value of the Data
• As both world demand for animal-sourced foods and global warming concerns rise, safe and effective strategies for enteric methane mitigation in dairy cows are in high demand. This dataset can be used to better understand the efficacy of many potential enteric methane mitigation options. • This large dataset with descriptive data and treatment means from in vivo dairy cow enteric methane studies can be used by both public and private researchers and advisors including nutritionists, environmentalists, and economists interested in cost-effective solutions to reduce global warming without compromising dairy farm sustainability.
• Evaluation of the data from many enteric methane mitigation experiments with dairy cows can provide indications regarding further research opportunities. Some strategies may prove to have limited research to date. The dataset may also help show potential nutrient and additive interactions needing further consideration and research.

Objective
Dairy organizations worldwide announced greenhouse gas neutrality goals. Mitigation of enteric methane emissions is necessary to achieve these goals. Many innovative solutions are being tested and considered. A dataset that compiles peer-reviewed, published research results on dietary nutrient reformulation and feed additives and their impact on both enteric methane and dairy cow performance can be used to evaluate promising options for reducing enteric methane emissions from dairy cows while maintaining dairy farm economic sustainability.

Data Description
One Microsoft Excel file containing manually extracted data from 213 peer-reviewed publications that includes 797 records (rows) and 162 variables (columns). The list of primary data sources is included within the Microsoft Excel file.

Experimental Design, Materials and Methods
The dataset was created from data collected from scientific publications identified through searches of the scientific literature. The bibliography used by Arndt et al. [1] , covering the period from 1963 to 2018, was supplemented with literature searches to cover the period between 2019 and 2022. The Web of Science Core Collection database was searched using the term "methane" in combination with "dairy", "cattle", "rumen", or "ruminant". Additionally, the search term "rumen" was used in combination with "energy balance", "energy metabolism", or "energy partitioning". A final search was conducted with the terms "enteric" and "dairy". Publications were included in the corpus when they met the following criteria: English language, detailed production responses, and, at a minimum, enteric methane and dry matter intake means with measures of variance. Data on 797 treatments (rows) from the 213 publications that met the inclusion criteria were manually extracted and compiled into a table containing 162 variables (columns). The variables include publication information, experimental design, animal definition, methane measurement method, and dietary nutrients, as well as treatment means and measures of variance for feed dry matter intake, rumen fermentation parameters, nutrient digestibility, nitrogen excretion, milk and milk components, and enteric methane, carbon dioxide, and hydrogen emissions ( Tables 1 , 2 ).

Ethics Statements
This study was conducted in compliance with the National Dairy Council 'Guiding Principles for Research and Communication of Results' [2] .

Data Availability
A global dataset of enteric methane mitigation experiments with lactating and non-lactating dairy cows conducted from 1963 to 2022 (Original data) (ScholarSphere (institutional repository managed by Penn State University Libraries)).