During the last centuries, agricultural practices have been drastically modified to meet the increasing global food demand linked to the growing population. This led to increased losses of nitrogen (N) to the atmosphere and aquatic systems, causing environmental pollution. In general, food systems are responsible for a third of global anthropogenic greenhouse gas (GHG) emissions, largely contributing to the climate change. Next to the US and India, the EU is one of the World´s leading producers of milk, with milk output reaching 234 million tons in 2021. On a global scale, livestock production contributes between 9% and 11% of total anthropogenic GHG emissions, with CH₄ livestock emission share of around 40%.  N pollution results from low protein nitrogen utilization efficiency (NUE), and global amount of N excreted annually by livestock is in a range of 10⁷ to 10⁸ T. NUE depends on cow genetics, farming management and feedstuff type and in dairy cows it roughly amounts to 25%. 

The European Farm to Fork strategy addresses the ambition of the EU Green Deal to significantly reduce N pollution and CH₄ emissions. However, to avoid concerns that actions raised to protect the environment in Europe result in increased pollution of other countries, sustainable intensification approaches to increase productivity of agro-food systems and simultaneously decrease impacts inside Europe and elsewhere, are needed. NITMETFUN addresses the need of enhancing the circularity in the agri-food sector at the farm level, which falls with the thematic call on the adaptation of Luxembourg´s agriculture to climate change. To foster an agro-ecological transformation of Europe implies reshaping the whole agro-food system, including circularity incrementation through crops and livestock reconnection. To address this concern, NITMETFUN will study the rumen anaerobic fungi (AF), which hold a huge potential to improve the nutrient profile for the host with concomitant reduction of CH₄ formation. Ideally, a higher share of AF in the rumen would allow to better valorise local, fibre-rich feedstuffs thus decreasing the dependency on high grain diet in dairy cows. Moreover, dependency on extra-European protein sources (i.e.,soybeans) in diets of dairy cows has been identified as another major problem that could be mitigated by an improved NUE. Both aspects are often considered paramount reasons for lack of sustainability and increased risk of food security in the European dairy sector.