Cyanide
Cynodon plectostachyus is a cyanogenic species that can produce high levels of hydrogen cyanide when overstressed by defoliation, drought and heavy grazing/trampling. In Kenya, the death of several cattle of the same herd was attributed to their consumption of Cynodon plectostachyus defoliated by larvae of the Lepidoptera Spodoptera exempta (Georgiadis et al., 1988). Enlarged thyroids and stillborn lambs have been reported on sheep grazing on giant star grass, which could be the consequence of the presence of cyanide or of low iodine content in the grass (Eisler, 2007).