Leucaena leucocephala has been utilized with limit as livestock feeds due to the existence of a toxic mimosine. So, it is necessary to induce mimosine toxicity to the experimental animals to study its cure and elucidation. Food intake of the chicks increased from the 1st day when the diet was changed to normal diet. Mimosine considerably existed in the feather and thyroid gland on the 20th day, but disappeared in the kidney, serum, liver and excretion. So, male broiler chicks were found to be rapidly and easily induced to mimosine toxicity by feeding 15% L. leucocephala seed powder diet for 12 days, and stored mimosines in the tissues rapidly reduced by feeding a normal diet.

Further studies of mimosine toxicity in broiler chicks were dene to cUarify a possibility of osteopathy. The mineral content aild density ef femur and the strength, dllctility, alld toughness fer the index of mechanical properties significantly decrensed in tlae 1% mimosine group, compared with these in the contrel and reshicted greups. The stiffhess had a decreasing tendency in the 1% mimosine group. Censequenay, it was co"cluded that ehicks fed ad libitum ft 1% mimosine diet for 12 days deyeloped osteopathy.

Psyllid, a noxious insect, has spread el'erywhere in the tropical and sub-tropical regions. This insect has an habit of infesting Leucaena leu(·ocephala. We have found that a crude enzyme of psyllid hydrolyzed mimosine, a strongly toxic substance for livestock, into 3-hydrox)'-4(lH)-pyridone, pyrm'ic acid, and ammonia. Besides, this enzyme was also able to cleave 3-hydroxy-4(lH)-pyridone.