October, 2023 | Agricultural Systems | Source |
Introduction:
Ireland’s beef sector, responsible for 37% of national greenhouse gas (GHG) emissions, presents key opportunities for climate mitigation through dairy-beef systems. Researchers from Teagasc and University College Dublin used the Grange Dairy Beef Systems Model (GDBSM)—a whole-farm bioeconomic model employing cradle-to-farm gate life cycle assessment (LCA)—to simulate emissions, economics, and protein efficiency in typical Irish systems. The study assessed 6 mitigation strategies, including earlier slaughter, slurry management, urease inhibitors, by-product feeds, clover pastures, and their combination, across Angus × Holstein–Friesian steers. It also examined trade-offs among GHG reduction, farm profitability, land use, and food security.
Key findings:
Combining all 6 strategies reduced GHG intensity by 21% and increased net margins per hectare by the same margin, demonstrating strong synergy between climate and economic benefits. Clover incorporation emerged as the most profitable stand-alone measure, boosting net margin by up to 25% and reducing GHG emissions per kg of carcass by 4–8%. By-product substitution in cattle feed led all systems to become net producers of human-edible protein, with efficiencies exceeding 4.0. Earlier slaughter age also reduced GHG intensity per kg of beef by 3–7%, though benefits varied with pasture use. Slurry management and urease inhibitors achieved modest emissions reductions (~3–4%) but lowered profitability due to added costs.
The study highlights that no single strategy optimizes all sustainability metrics. However, integrated approaches—especially those leveraging clover and feed by-products—offer significant promise for low-emissions, profitable dairy-beef systems. Future work should explore region-specific soil carbon sequestration potential to further reduce system-level emissions.
Graphical Abstract
.jpg)
