10.18453/rosdok_id00004473 Honerlagen, Hanne Hanne Honerlagen http://d-nb.info/gnd/1312049391 https://orcid.org/0000-0001-6860-0131 Universität Rostock 2022 500 Natural sciences 630 Agriculture 2022 en https://purl.uni-rostock.de/rosdok/id00004473 urn:nbn:de:gbv:28-rosdok_id00004473-5 Enhancing the nitrogen (N) utilisation efficiency (NUE) of dairy cows by breeding selection was considered relevant for environmental footprints, feeding costs and animal health. It was hypothesised that cow-individual NUE is determined by the entire “holobiont”, thus by the host genome and the rumen microbiome. In this context four study approaches were conducted, which focused on the host genome-trait, the host genome-rumen microbiota and the entire host genome-rumen microbiota-trait axis, aiming for a holistic exploration of cow-individual NUE as a pre-step for future breeding strategies.