As a large dairy producer, the Netherlands has set goals to the reduction of greenhouse gas emissions from the dairy sector. Inherent to those goals are the reduction and measurement of methane emission by dairy cows. KeyToxicology is experienced with different strategies to reduce (e.g. feeding) and measure (e.g. proxies, such as milk composition) methane emissions. With resource to scientific and field data, KeyToxicology can qualitatively and quantitatively predict methane emission from dairy cows. This is important to better understand the measures taken to achieve a more sustainable dairy chain.