Carbon footprint and environmental impacts of feeding grape pomace to dairy cows in California

e/kg ECM for the control, gp10%, and gp15% diets, corresponding to reductions of 15.8% and 19.3%, respectively. Similar reductions were observed for water-related impact categories, ranging from 17.6% to 23.2% for gp10% diets and from 23.8% to 32.6% for gp15% diets. Reductions in soil-related impact categories ranged from 17.3% to 23.8% for gp10% diets and from 22.9% to 34.6% for gp15% diets. Uncertainty analyses indicated relatively low variability within chosen data sources. However, temporal uncertainty, geographic extrapolation, and model structure differences may be underestimated by pedigree methods and should be considered when interpreting absolute values. Overall, inclusion of grape pomace in dairy cow diets reduced the carbon footprint and environmental impacts related to water and soil without adversely affecting milk production.