Diets with 0.0, 0.5,2.0, or 4.0% ground-aerIal parts of Senecio vernalis were fed to groups of 10 laying hens for 210 d. Plant alkaloid content was 0.14% with 8.57% in the basic form and 91.43% in the N-oxide form. Specific alkaloids were senecionin (66.65%), senecivernin (10.37%), seneciphylline