Dr. Clodagh Ryan, ICBF, recently completed her PhD on Genetic Selection for Reduced Methane Emissions: Trait Definition and Evaluation in Irish Beef Cattle.
This research examined how genetics can be used to reduce methane emissions from Irish beef cattle. Methane is the largest source of agricultural greenhouse gases in Ireland, and lowering it is essential for meeting national climate goals.
Between 2018 and 2024, methane and carbon dioxide were measured from more than 1,800 growing cattle in the ICBF performance test environment using GreenFeed units. These data were combined with feed intake, growth, carcass, and pedigree records.
The research showed that cattle naturally differ in how much methane they produce, and that these differences are heritable. This means methane can be reduced through breeding, in the same way that traits such as growth and carcass quality have already improved over time in Ireland.
The work also looked at how methane relates to key performance traits, and tested what would happen if a methane trait were added to the Irish Terminal Index. The results showed that meaningful reductions in emissions are possible through genetic selection, while still supporting progress in economically important traits.
This research produced several peer reviewed open access publications, including:
- Phenotypic relationships and repeatability of methane emissions in beef cattle (JAS 2022) DOI: 10.1093/jas/skac349
- Definitions of methane traits for genetic evaluations (JAS 2024) DOI: 10.1093/jas/skae034
- Genetic correlations between methane and economically important beef traits (JAS 2025) DOI: 10.1093/jas/skaf162
- Incorporating methane into Irish beef breeding goals (Livestock Science 2025) DOI: 10.1016/j.livsci.2025.105837
Together, these outputs provide the scientific foundation needed to include methane traits in national breeding programmes and demonstrate that breeding lower methane cattle is a practical long term solution.