ABSTRACT
Livestock is a key element of organic agriculture. The concept of closed nutrient cycles requires the close integration of crop and livestock systems whenever possible within a farm, or at least within regions (e.g. IFOAM, 2014; Bioland, 2016; Bio Suisse, 2016). Ruminants play a particularly important role in integrated organic systems, since they can efficiently utilize grassland resources, legume forages from crop rotations and crop residues, and they provide valuable manure for the soil. However, large amounts of concentrates are still fed to organic cattle, requiring the transport of soya bean on a large scale across the globe (Früh et al., 2014) with severe ecological and social consequences (Pellentier and Tyedmers 2010; Semino et al., 2009). Furthermore, the demand for arable land areas to produce cereals for organic ruminant production is still very high. This is a status quo that should be overcome against the background of the environmental and social claims of organic agriculture (IFOAM, 2014). On the other hand, it is particularly the ruminal digestion of fibre which produces methane, thus directly impacting climate change dynamics in a most problematic way (Beauchemin et al., 2008).
