Selective and low transfer of pyrrolizidine alkaloids from Jacobaea vulgaris Gaertn. into muscle and liver of dairy cattle, goat and sheep

1,2-unsaturated pyrrolizidine alkaloids and their N-oxides (PA/PANO) are plant toxins that are produced by several hundreds of plant species. Due to the pronounced liver toxicity and carcinogenicity of certain PAs, their presence in food and feed has raised concern. However, since PA-producing weeds cannot generally be prevented on grassland and Senecio species often occur in high densities, the transfer of PAs into muscle and liver of dairy cattle, goat and sheep was determined. In 28-day feeding studies extracts of tansy ragwort (Jacobaea vulgaris Gaertn.) were administered orally in three dose levels per animal species. Of the administered Senecio PAs only jacobine, jaconine and jacoline could be detected in relevant quantities by LC-MS/MS in the muscle and liver tissues of the three animal species. The calculated transfer parameters show a low transfer of total PAs into muscle (transfer factors: 0.0004–0.0009) and liver (transfer factors: 0.0008–0.0030), which is lower than reported for other typical contaminants and residues in the literature. This selective transfer can be explained by the rumen passage, during which the other Senecio PAs are largely and rapidly transformed to fully saturated metabolites. These ruminal metabolites were not detected in muscle and liver. No evidence of bioaccumulation of PAs in muscle and liver was observed.