During the Sheep Ireland Industry Meeting, speakers highlighted the latest research to be included in the National Sheep Breeding Improvement Programme’s 2026 Genetic evaluation and €urostars rating.
Dr. Jonathan Herron (Teagasc) presented the research behind the addition of carbon values to some traits in the €uroStars 2026 evaluation.
How Emissions are Calculated
Agricultural Greenhouse gases (GHG) emissions arise from multiple sources such as livestock, vehicles, fertiliser and there is a large variation between the emissions from these sources.
The Life Cycle Assessment (LCA) model extends the bio‑economic model to calculate GHG emissions from cradle to farm gate, capturing:
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Carbon dioxide (CO₂)
It incorporates every emissions source on a sheep farm enabling a full picture of total farm emissions and carbon footprint.
Carbon Values
Economic values of traits in the €uroStar indexes are based on the change in profit per unit change in the trait under investigation holding all other traits constant.
A carbon value is the change in total emissions per unit change in the trait under investigation holding all other traits constant
- Only traits that affect productivity (and therefore emissions) assigned carbon values
- Total carbon value is converted to an economic value by a price per tonne of carbon
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- Increased economic weight of traits that reduce emissions
- Reduced economic weight on traits that increase emissions
- The carbon value for traits are derived from both the LCA (non-methane emissions) and measured methane.
This approach shifts breeding priorities toward more efficient animals and more sustainable farming systems.
Click below to view Dr. Jonathan Herron’s Presentation:
