Our aim is to develop and implement a breeding tool that improves the feed efficiency in Danish dairy cattle. Feed expenses constitute 70% of the variable costs, and are thus the biggest variable cost for the cattle farmer. Even small improvements of the feed efficiency in cattle will have great influence on the farmer’s economy. At the same time, a higher feed efficiency means less methane emission, which is a benefit for the environment. Genetic selection is a strong tool for the improvement of quantitative traits such as feed efficiency, as it is cumulative and continuing. The genes of a cow have the same effect every day, and the effect is passed down to future generations. With this project, we wish to develop and implement a selection tool that makes it possible to select cows, which are more feed efficient and environmentally friendly. This will be done by applying data from experimental and commercial farms. The tool will be developed in a way that information from both direct registrations of feed intake as well as registrations for indicator traits such as milk, exhalation, activity, and blood are included as information sources. Simultaneously, new biometrical methods will be developed that can handle this type of data, just as the economic value of trait, and by that the excess yield for the farmer, is quantified. In general, the project will contribute to a more resource efficient food sector, reduce the emission of greenhouse gases, increase the global competitiveness of Nordic breeding, and manifest its lead within holistic breeding.