Sustainability & efficiency

Emission reductions and economic ramifications of methane selection within Irish ruminant breeding indexes

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Abstract

Sustained reduction in emissions is a key challenge to the development of sustainable agricultural systems, with two-thirds of Irish agricultural greenhouse gas emissions, for example, derived from livestock production. In pursuit of agricultural sustainability, selection of genetically superior animals using breeding indexes is recognized by the Irish marginal abatement cost curve to deliver cost-effective emission reductions. The objective herein is to estimate the long-term expected emission reductions, as well as the associated industry-level economic ramifications, derived from the Irish sheep, beef and dairy breeding indexes. Estimates will assess the Irish ruminant breeding indexes both with and without (i.e., their current format) a methane production trait included in the indexes.Selection index theory, alongside variance components and index weightings provided by the Irish Cattle Breeding Federation, were used to determine the expected trait changes per unit change in each index. To simulate the inclusion of methane production in the indexes, carbon prices of €80 and €300 per tonne of CO2 were used to calculate the trait's economic weight. The outputs from the selection index modelling were then applied in a recursive geneflow model to estimate the industry-level economic ramifications of selection for reduced methane emissions.The output from the selection index modelling determined that current Irish dairy and sheep breeding indexes (which exclude methane traits) are estimated to provide annual emission reductions, with further reductions expected from the inclusion of methane production in the indexes (Table 1). Moreover, outputs estimate that the inclusion of methane production in the Irish ruminant breeding indexes will provide industry-level reductions between 0.48 and 1.20 Mt of CO2 (depending on the carbon price) over 10 years, relative to the status quo; this equates to reductions between 2.5% to 6.1% of total Irish agricultural emissions by 2036. Moreover, the industry-level opportunity costs associated with emission reductions derived from methane trait selection, which are a result of compromises in the genetic progress made on conventional genetic traits that underline production efficiency and farm profitability, vary from €1.75M to €39.29M across the production systems of interest, depending on the carbon price assumed.Results highlight that current Irish breeding indexes are relatively efficient at reducing emissions within ruminant production systems, with modest increases in reductions derived from the inclusion of methane production in the indexes. Moreover, the associated opportunity costs highlight the need for a balanced approach with regard to maintaining genetic progress in conventional profit-related traits and also achieving methane reductions.

Keywords: 2026

How to Cite:

Amer, P., Evans, R., Hely, F., Kenny, D. & Sise, J., (2026) “Emission reductions and economic ramifications of methane selection within Irish ruminant breeding indexes”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2269622. doi: https://doi.org/10.31274/wcgalp.23402

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