Signpost Series: Feed Additives and Methane Production

Why It Matters

Cutting livestock methane through feed additives and breeding can lower Ireland’s agricultural carbon footprint without sacrificing output, delivering both environmental and economic benefits for producers and policymakers.

Key Takeaways

• Agriculture contributes ~40% of Ireland’s greenhouse gas emissions.
• Methane accounts for 75% of agricultural emissions, driven by rumen fermentation.
• Feed additives and grass management can cut methane without reducing intake.
• Breeding low‑methane cattle requires focusing on methane yield, not just output.
• In‑vitro screening at Grange identifies promising additives like seaweed and lipids.

Summary

The Signpost webinar focused on feed additives and other strategies to curb methane emissions from Irish livestock, featuring research officer Emily Roskam and climate adviser Mave Hagen. The session highlighted that agriculture accounts for roughly 40% of Ireland’s greenhouse‑gas output, with methane representing about three‑quarters of that share, primarily from rumen fermentation.

Key insights included the heritability of methane production (0.2‑0.3), the need to select for methane yield rather than absolute emissions, and the impact of diet and pasture management on methane output. Grange’s in‑vitro and rumen simulation facilities enable rapid screening of additives—such as seaweed extracts, lipids, nitrates, and essential oils—while measuring digestibility and animal performance. Studies showed that silage quality, grazing height, and grass‑clover mixes affect both intake and methane, with higher‑quality forage reducing emissions and improving weight gain.

Notable examples cited were ICBF’s 2024 breeding values identifying bulls that emit 9‑10 g less methane per day, and field trials where grass‑clover pastures increased daily live‑weight gain by up to 23 kg without harming methane mitigation when managed correctly. A large Methabate project screened dozens of additives, pinpointing several farm‑ready candidates for pasture‑based systems.

The implications are clear: integrating genetic selection with targeted feed additives and optimized pasture management can deliver measurable methane reductions while sustaining or enhancing productivity. This creates a pathway for Irish producers to meet tightening emissions regulations, access carbon‑credit markets, and improve profitability through more efficient feed use.

Original Description

On this episode of the Signpost Series which took place on Friday, 20 March, host Cian Condon, KT Outreach & Innovation Specialist, Teagasc was joined by Emily Roskam, Teagasc to discuss feed additives and methane production. A questions and answers session took place at the end of the presentation, which was facilitated by Meabh O'Hagan, Climate Action and Sustainability Advisor, Teagasc.