Incorporating the carbon sub index into Irish sheep breeding program
ORCID
https://orcid.org/0009-0004-8837-9074
Department
Biological Sciences
Year of Study
2024-2025
Full-time or Part-time Study
Full-time
Level
Postgraduate
Presentation Type
Oral Presentation
Supervisor
Deirdre Purfield
Supervisor
Jonathan Herron
Abstract
Background
Efforts to reduce greenhouse gas (GHG) emissions have intensified in the agricultural sector, with animal breeding recognised as a key mitigation strategy. Despite this, GHG are currently missing from sheep breeding goals. Incorporating GHG as carbon in the selection index could facilitate genetic selection of lower GHG emitting animals. This study aims to add a carbon sub-index into the existing national sheep breeding index.
Methods
Teagasc sheep life cycle assessment model was used for calculation of GHG. The carbon value was obtained by converting all GHG emissions to CO2 equivalent using IPCC methodology. The economic value of carbon per trait was then calculated as a change in total GHG emissions per unit change in the trait, holding all other traits constant. Selection index theory was applied to determine the impact of a carbon sub-index on traits within the terminal and replacement breeding indexes.
Results
The carbon economic value was: -€0.19 lamb surviving at birth, €20.08 number of lambs born, €0.03 ewe mature weight (replacement), €0.17 ewe mature weight (maintenance), €0.09 days to slaughter (per day), €0.15 carcass fat (per score). Carbon constituted 9.96% in terminal index and 17.86% in replacement index.
Conclusion
Positive carbon economic values indicate that selection for certain traits may increase GHG emissions, while negative values for others suggest possibility of reducing emissions without compromising profitability. The replacement index will place greater emphasis on carbon emissions than terminal index as it aims to produce ewes that will remain in the flock for the next breeding season.
Keywords:
carbon, selection index, life cycle assessment, sheep
Start Date
16-6-2025 10:00 AM
End Date
16-6-2025 10:15 AM
Recommended Citation
Chipondoro, Lucy, "Incorporating the carbon sub index into Irish sheep breeding program" (2025). ORBioM (Open Research BioSciences Meeting). 5.
https://sword.mtu.ie/orbiom/2025/oral1/5
Incorporating the carbon sub index into Irish sheep breeding program
Background
Efforts to reduce greenhouse gas (GHG) emissions have intensified in the agricultural sector, with animal breeding recognised as a key mitigation strategy. Despite this, GHG are currently missing from sheep breeding goals. Incorporating GHG as carbon in the selection index could facilitate genetic selection of lower GHG emitting animals. This study aims to add a carbon sub-index into the existing national sheep breeding index.
Methods
Teagasc sheep life cycle assessment model was used for calculation of GHG. The carbon value was obtained by converting all GHG emissions to CO2 equivalent using IPCC methodology. The economic value of carbon per trait was then calculated as a change in total GHG emissions per unit change in the trait, holding all other traits constant. Selection index theory was applied to determine the impact of a carbon sub-index on traits within the terminal and replacement breeding indexes.
Results
The carbon economic value was: -€0.19 lamb surviving at birth, €20.08 number of lambs born, €0.03 ewe mature weight (replacement), €0.17 ewe mature weight (maintenance), €0.09 days to slaughter (per day), €0.15 carcass fat (per score). Carbon constituted 9.96% in terminal index and 17.86% in replacement index.
Conclusion
Positive carbon economic values indicate that selection for certain traits may increase GHG emissions, while negative values for others suggest possibility of reducing emissions without compromising profitability. The replacement index will place greater emphasis on carbon emissions than terminal index as it aims to produce ewes that will remain in the flock for the next breeding season.