Sustainability & efficiency

Genetic Evaluation of Methane Emissions in U.S. Holstein Cattle

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Abstract

Methane is a major greenhouse gas produced during enteric fermentation in ruminants, serving as an indicator of both rumen microbial activity and overall feed efficiency. Understanding the genetic basis of methane emissions provides an opportunity for long-term and cumulative reduction of emissions through selective breeding. The objectives of this study were to (1) estimate the genetic parameters of methane production, (2) assess its genetic correlations with key feed efficiency traits: body weight (BW), energy-corrected milk (ECM), dry matter intake (DMI), and residual feed intake (RFI), and (3) develop a genomic evaluation framework for methane production in the U.S. dairy population. Data were collected from 1,169 uniparous and multiparous Holstein-Friesian cows (n = 1, 2, or 3) housed at the STgenetics research herd between 2023 and 2025 using GreenFeed systems. Univariate and multi-trait animal models were applied to estimate heritabilities and genetic correlations using the BLUPF90 software suite. Pedigree information was used to define genetic relationships and estimate variance components, while genomic data were incorporated to estimate genomic estimated breeding values (GEBVs). The heritability estimate (± SE) for methane production was 0.28 ± 0.05, suggesting that genetic progress through selection is achievable. Genetic correlations of methane production with BW, ECM, DMI, and RFI were 0.28 ± 0.16, 0.06 ± 0.22, 0.60 ± 0.18, and 0.15 ± 0.01, respectively. The GEBVs for methane production ranged from -61 to 51 g/d, with a standard deviation of 18.98 g/d in the training population, and from -78 to 66 g/d with a standard deviation of 13.90 g/d in the testing population. The average reliability of breeding values for methane production was 50% in the training and 25% in the testing populations. Methane production was favorably correlated with RFI which indicated that selection of high feed efficient animals will produce less methane. The positive genetic correlations of methane production with BW and DMI indicated that selection for reduced methane emissions should be carefully balanced with overall feed efficiency and productivity. Establishing a national genetic evaluation for methane emissions in U.S. dairy cattle represents a major advancement toward quantifying and mitigating the environmental footprint of the national herd, supporting climate-smart dairy production and greenhouse gas reduction goals.

Keywords: 2026

How to Cite:

Deeb, N., Johnson, J., Khanal, P., Kukor, I. & Ross, P., (2026) “Genetic Evaluation of Methane Emissions in U.S. Holstein Cattle”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286649. doi: https://doi.org/10.31274/wcgalp.24079

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