The purpose of the project is to improve the competitive performance for Danish milk producers and the cattle breed association VikingGenetics, as well as increase the utilization of resources in the dairy cattle sector by using the full potential inn crossbreeding between dairy breeds. Crossbreeding is largely used in other production areas in order to obtain crossbreed richness, but has a limited use in dairy cattle due to lack of management tools. The project will result in crossbred cows with increased health, fertility and durability. This leads to approximately 200 mio. DKK per year in further economic effects with the milk producers, a lower food consumption per kilo value material, and a lower CO2 emission per kilo value material. Furthermore, a larger genetic diversity within the breeds is obtained. The project’s goal is reached by developing and implementing decision support tools in the form of 1) genetic values for crossbred animals based on genomic information, 2) new modules for the simulation programme SimHerd, making it possible to support the decisions the individual milk producer has to make for his herd regarding crossbreeding, and 3) new modules for the insemination plan programme, making it possible to maximise the crossbreed richness in each mating by means of genomic information. Furthermore, and as the first, the project will build up a decision base for the design of purebred lines of dairy cattle, selected for producing efficient crossbred offspring contrary to present day, where the breeding work solely focuses on improving the performance of the purebred animals.