Influence of grass pellet production on pyrrolizidine alkaloids occurring in Senecio aquaticus-infested grassland

Abstract

1,2-Dehydro-pyrrolizidine alkaloids (PA) and their N-oxides (PANO) exhibit acute and chronic toxic effects on the liver and other organs and therefore are a hazard for animal and human health. In certain regions of Germany, an increasing spread of Senecio spp. (ragwort) on grassland and farmland areas has been observed during the last years leading to a PA/PANO-contamination of feed and food of animal and plant origin. This project was carried out to elucidate whether the process of grass pellet production applying hot air drying influences the content of PA and PANO. Samples of hay (n = 22) and grass pellets (n = 28) originated from naturally infested grassland (around 10% and 30% dominance of Senecio aquaticus) and from a trial plot with around 50% dominance. Grass pellets were prepared from grass originating from exactly the same plots as the hay samples. The samples were analysed by liquid chromatography-tandem mass spectrometry for PA/PANO typically produced by this weed. The results of the study revealed that PA/PANO levels (predominantly sum of senecionine, seneciphylline, erucifoline and their N-oxides) in hay ranged between 2.1 and 12.6 mg kg dry matter in samples with 10% and 30% dominance of S. aquaticus, respectively. Samples from the trial plot (50% dominance) had levels of up to 52.9 mg kg. Notably, the hot air drying process during the production of grass pellets did not lead to a reduction of PA/PANO levels. Instead, the levels in grass pellets with 10% and 30% S. aquaticus ranged from 3.1 to 55.1 mg kg. Grass pellets from the trial plot contained up to 96.8 mg kg. In conclusion, hot air drying and grass pellet production did not affect PA/PANO contents in plant material and therefore, heat-dried products cannot be regarded as safe in view of the toxic potential of 1,2-dehydro-pyrrolizidine alkaloids.

Controlling the abundance of a native invasive plant does not affect species richness or functional diversity of wet grasslands

“…In the past decades, J. aquatica has become more common in the pre‐alpine grasslands of Austria, Germany and Switzerland (Suttner et al, 2016). As all parts of the plant contain pyrrolizidine alkaloids, which are toxic to livestock and humans (Gottschalk et al, 2018), local hotspots pose essential problems to farmers managing such grasslands. Previous studies already focused on practical control measures in agricultural grasslands (Sargent, 2011; Suter & Lüscher, 2011; Bassler et al, 2016), while management recommendations for ecologically valuable conservation grasslands are lacking.…”

A sensitive LC–MS/MS method for isomer separation and quantitative determination of 51 pyrrolizidine alkaloids and two tropane alkaloids in cow’s milk

“…The combined occurrence of erucifoline and senkirkine in pasteurised milk 5 indicated plants of the genus Senecio or Jacobaea, respectively, as the causative source for the feed contamination [19,52]. This milk, labelled as hay milk, was obtained from a regional marketer in the Bavarian district Oberallgäu, an area known for its spread of marsh ragwort (Jacobaea aquatica).…”

Summer rain and wet soil but not management correlate with the distribution of a toxic plant in production grasslands

“…As J. aquatica produces considerably larger achenes, long-distance dispersal has apparently even less importance for this species [10]. The high pyrrolizidine content of J. aquatica makes the species poisonous for livestock and cattle, and can even be harmful to humans via milk [35], [13]. In Bavaria, J. aquatica can be found throughout the entire federal state, while occurrence in warmer regions with lower rainfall is mainly restricted to moist soils [16].…”

“…or ragwort species (Senecio and Jacobaea spp.) which contain cytotoxic colchicine or hepatotoxic pyrrolizidine alkaloids, respectively [10], [11], [12], [13]. As these toxic substances can cause severe health problems to livestock and humans, they can question further forage usage of the grasslands [10], [14].…”