Straw disposal
The flax crop generates large amounts of flax straw, and the disposal of this by-product is a major environmental issue in flax-growing regions. Flax straw is poorly degraded and difficult to plough down in the soil, since the fibres wrap themselves around and/or plug disks, wheels and shovels. For that reason, flax straw is often burned on the ground, which causes air pollution and health concerns (FCC, 2014; CLA, 2014). However, there are now many other uses for flax straw, such as turning it into an alternative fibre source or as a biofuel, which may alleviate the environmental problems caused by this residue (Comeau, 2006; FCC, 2014).
CH4 emissions
Feeding ruminants with linseeds, particularly extruded linseeds, has been shown to reduce CH4 emissions. In dairy cows fed maize silage + 5% raw linseeds, extruded linseeds or linseed oil, methane emission was reduced by 12, 38 and 64%, respectively (Martin et al., 2008). In a further trial, increasing the level of extruded linseeds (5, 10 and 15% of the diet) in lactating dairy cows rations reduced CH4 emissions by respectively 10, 16 and 41%, respectively (Martin et al., 2010). Adding linseeds to the grass or maize-based diets of fattening bulls reduced CH4 emissions during the 18 months of the trial (Eugène et al., 2011). Methane production decreased (up to 30%) with increasing ground linseed levels (0 to 15%) (Velez, 2012).