Exposure assessment of cattle via roughages to plants producing compounds of concern

Food producing animals are exposed to biologically active plant compounds through feed and roughages, presenting a potential risk to the animal but also consumers of food of animal origin. To evaluate to which plant compounds of concern dairy cows in the Netherlands are exposed, a ranking filter model was developed, combining information on abundance of plant species in vegetation plots in the Netherlands (183,905 plots of three different vegetation types) with plant-compound combinations (700), and with consumption data of fresh grass, grass silage and corn silage by cattle. The most abundant plant genera are those producing cyanogenic glycosides, coumarins and benzofuranocoumarins, being predominantly fodder plants (alfalfa, clover and some grasses) considered to be safe. Highest exposures were estimated for plant genera producing piperidine alkaloids (horsetail), furanocoumarins (parsley and relatives), pyrrolizidine alkaloids (Symphytum, Senecio, Leucanthemum, Eupatorium) and essential oils. The current results allow to prioritise future scientific research on these compounds.