Cyanogenese in Futterpflanzen und Auswirkungen in der Wiederkäuerernährung

The high number of secondary plant compounds accounts for its variability. Cyanogenic glucosides are derived from aminoacids and are stored as hydrocyanic acid (HCN) in plants. Cyanogenic glucosides are not toxic as long as the glycoside is not split by the respective enzyme. Their function in plants is controversially discussed and for a range of plant species cyanogenic glucosides are supposed to be involved in the defense mechanism of the plants. Sorghum is substituting corn in cropland areas in Europe, the summer drought and crop rotation being the most important reasons. White clover contains variable amounts of cyanogenic glucosides. Two genes (Ac and Li) are involved in the formation of cyanogenic glucosides, resulting in white clover cultivars with low content of cyanogenic glucosides. Due to higher pH-values in the rumen, ruminants consuming cyanogenic glucosides may react sensitive. White clover is normally limited to 20–30 % in grassland botanical composition to avoid high crude protein content in autumn. Using Sorghum as forage or seeds (as constituents of concentrates) is nowadays acceptable due to breeding progress using hybrids. Farmers, who are conscious about the problem with cyanogenic glucosides, pay attention to use cultivars with low contents.