Sustainability & efficiency

Genetic Selection for Reduced Enteric Methane Emissions in Irish Beef Cattle: Measurable Gains with Minimal Trade-offs

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Abstract

Breeding programs are increasingly recognised as a central tool for achieving climate resilience in livestock production, yet direct selection for reduced enteric methane emissions remains limited in beef cattle populations. This study evaluated the potential of incorporating an enteric methane production trait into the Irish Terminal Index, which defines the national breeding objective for beef herd cattle destined for slaughter. The current index includes a Carbon sub index derived from life cycle assessment methodology but does not directly account for individual variation in enteric methane output. Using genetic parameters from routinely evaluated traits coupled with prototype methane parameters estimated from 1,508 beef cattle with individual methane phenotypes recorded using GreenFeed systems, a series of selection index models were developed to compare outcomes with and without a direct enteric methane trait under differing carbon price assumptions which reflect current and projected policy scenarios. The modelled scenarios allowed the partitioning of enteric and non-enteric emissions with the enteric emissions allocated to the direct methane measure whilst the remaining non-enteric emissions remaining in the life cycle assessed framework. Results indicate that selection emphasis based on the current index, predicted daily methane emissions are still increasing slightly by 2.14 grams per day. The inclusion of a direct enteric methane production trait reversed this trend, realising reductions of up to 4.2 grams per day per animal depending on the environmental weighting applied. Genetic progress in economically important traits remained favourable, with carcass weight increasing by approximately 14 kilograms and feed intake declining by 0.3 kilograms dry matter per day under the most environmentally weighted index. Selection responses for calving, docility and carcass conformation traits were largely unaffected, and overall economic gain remained comparable to the current national breeding goal. When scaled to the national suckler herd, the predicted genetic change corresponds to an annual reduction of 27,400 tonnes of carbon dioxide equivalent, or roughly 0.13 percent of total Irish agricultural greenhouse gas emissions in 2023. Although this estimate applies only to the suckler beef sector, extending similar selection strategies to dairy and dairy beef animals, which account for over 60 percent of cattle slaughtered nationally, could deliver substantially greater cumulative reductions over time.These results demonstrate that enteric methane can be effectively integrated into national breeding goals with minimal trade-offs in production performance. As methane phenotyping expands and genomic prediction accuracy improves, breeding for reduced emissions will form a critical component of climate smart beef systems and make a measurable contribution to achieving national emission reduction commitments.

Keywords: 2026

How to Cite:

Crosson, P., Evans, R., Kenny, D., Purfield, D. & Ryan, C., (2026) “Genetic Selection for Reduced Enteric Methane Emissions in Irish Beef Cattle: Measurable Gains with Minimal Trade-offs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2281886. doi: https://doi.org/10.31274/wcgalp.23462

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