Anthelmintic resistance has become a serious problem worldwide especially for small ruminants but it is also rising for cattle. The sustainability to maintain the efficacy of anthelmintics is an important objective. Furthermore, reduction of anthelmintic use is desired to assure safe and high quality food. Therefore targeted selective treatment (TST) systems should be developed. Through TST the use of anthelmintics can be reduced and selection pressure on sensible endoparasite isolates decreases. The current project aims at 1st the investigation of the current efficacy of macrocyclic lac-tone anthelmintics in first season grazing cattle in Northern Germany and 2nd to com-paratively investigate different approaches to TST such as body weight, body condition-ing scores (BCS) and egg output (EPG)