Hegarty, Schinckel and Court1 have reported the use of isolated mimosine (β-[N-(3-hydroxypyridone-4)]-α-aminopropionic acid) in metabolism investigations with sheep. They reported that the major metabolite 3,4-di-hydroxypyridine (DHP) was present in the urine, and that degradation of mimosine to DHP occurred in the rumen, the animal being unable to detoxicate the material after absorption. No comparable work on the fowl has been located in the literature.