Optimizing Dairy Production to Reduce Environmental Impacts

Research on dairy production has highlighted the need for a more sustainable approach to reduce environmental impacts associated with the increasing demand for milk-based products. A recent study from the Ryan Institute at the University of Galway in Ireland has combined life cycle assessment and machine learning to identify potential reductions in environmental footprints of grass-fed dairy systems. The study found that by breeding for "LCA-designed ideotypes," the environmental impacts of grass-based milk can be substantially reduced.

Key Takeaways:

• Global demand for ruminant milk-based products is increasing, contributing to environmental impacts associated with dairy production.
• The study used a machine learning model to analyze 10,000 graduated scenarios and revealed complementarities and trade-offs across different environmental impacts.
• The researchers identified dry matter digestibility, crude protein, and chemical nitrogen use as key drivers of environmental impacts in dairy systems.
• The optimal ryegrass ideotype identified for grass-based dairy systems can reduce global warming potential by 36.7%, acidification potential by 31%, eutrophication potential by 29%, and fossil resource depletion by 11% compared to current levels.
• The study concluded that a more systems-based approach to livestock and forage breeding is needed to reduce the environmental impacts of dairy production.

Statistics:

• Milk produced in ryegrass-based dairy systems in Ireland was associated with environmental impacts of 1.08 kg CO-eq, 0.0066 kg PO-eq, 0.013 kg SO-eq, and 1.62 MJ-eq per kg fat- and protein-corrected milk (FPCM).
• The annual per-hectare loads of CO-eq, PO-eq, SO-eq, and MJ-eq were 9281.21 kg, 56.75 kg, 108.21 kg, and 14,025.16 MJ/kg, respectively.
• The XGBoost Regressor achieved an outstanding R value of 99% in estimating the LCA impacts.
• Principal component analysis and explainable artificial intelligence analyses identified dry matter digestibility, crude protein, and chemical nitrogen use as key drivers of environmental impacts in dairy systems.

Sources:

• Science of The Total Environment, "Optimizing selective breeding of livestock and forage crops to reduce the environmental impacts of grass-based dairy production by combining life cycle assessment and machine learning," (Science of The Total Environment, 2025;1003:180615).
• University of Galway, Ryan Institute, "Research Results from Ryan Institute Update Knowledge of Global Warming and Climate Change (Optimizing selective breeding of livestock and forage crops to reduce the environmental impacts of grass-based dairy production by combining life cycle ...)," (Global Warming Focus, October 27, 2025; p 984).