Infections with gastrointestinal nematodes have a major impact on the productivity of grazing cattle. Young stock is especially sensitive, because these animals have not yet developed immunity. Combating worm infections is based on the regular administration of wormers (anthelminthics). However, often the timing and frequency of deworming is not based on diagnostic information about the level of infection, making deworming inefficient. One reason for this is that the available diagnostic tools are complex and expensive compared to the cheap and easy to use anthelminthics, thus encouraging frequent use of anthelmintics. However, this approach is not sustainable, not cost-effective, not consistent with 'evidence based medicine' and is threatened by anthelminthic resistance. In order to better integrate deworming in grazing management, so that anthelminthics can be used in a more targeted manner, user-friendly, non-invasive and inexpensive decision support tools are needed, which can advise the veterinarian and the farmer, preferably before the start of the grazing season, on measures to be taken. Several building blocks for a targeted use of anthelminthics are already in place: (i) a prototype tool, which will be validated and optimized in this project (ii) the intention of livestock farmers to apply diagnostic tools for helminth infections has been identified, (iii) there are sufficient technological possibilities from precision agriculture (ICT, apps) to apply monitoring and control measures and (iv) the growing interest in integrated business management on dairy farms. The innovation goal of this project is to integrate these building blocks into a tool that supports the farm manager in decisions that support sustainable dairy farming at the level of the individual farm (economic added value), the sector (reduced risk of resistance) and society (sustainable grass-based production).