In Holland organic dairy farming emits the same amount of greenhouse gases per kilogram of milk as conventional dairy farming. This is the conclusion of Wageningen Livestock Research commissioned by the Ministry of Agriculture. Per hectare, the greenhouse gas emissions of organic dairy farming are about a third lower than those of conventional dairy farming, but the emissions in CO2 equivalents per kilogram of milk produced are the same. Organic dairy cows produce more rumen methane per kilogram of milk because their rations contain more grass silage and less concentrates and maize silage. Milk production is also lower, so that the total emissions can be spread over less milk. Because of more outdoor grazing, organic cows produce less methane from manure, but this is offset by higher nitrous oxide emissions from manure and urine in the meadow.