Optimising nitrogen use in dairy farming: evaluation of ruminal crude protein degradation and protein value of forages [Elektronische Ressource] / Bronwyn Lee Edmunds. Landwirtschaftliche Fakultät

Institut für Tierwissenschaften der Rheinischen Friedrich-Wilhelms-Universität Bonn Optimising nitrogen use in dairy farming: Evaluation of ruminal crude protein degradation and protein value of forages Inaugural-Dissertation zur Erlangung des Grades Doktor der Agrarwissenschaften (Dr. agr.) der Hohen Landwirtschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität zu Bonn vorgelegt im August 2011 von B. Sc. (hons.) Bronwyn Lee Edmunds aus Bridgetown, Australien Referent: Prof. Karl-Heinz Südekum Korreferent: PD Dr. Jürgen Schellberg Tag der mündlichen Prüfung: 22. Dezember 2011 Erscheinnungsjahr: 2012II Summary Summary Nitrogen (N) utilisation in dairy farms is inefficient. High N inputs through expensive protein concentrates and fertilisers are not in balance with agricultural outputs (reproduction, growth, milk). Large losses of N occur through animal excretion and its poor management, as well as leaching from fertilised soils, leading to environmental pollution. Nitrogen inputs are also expensive to farmers and the cheapest sources are often imported soy products. A high dependency on imports, however, is detrimental to the environment and economy, thus local sources of protein, such as forages, are preferable.