Under the ritsuryo system, one bokucho, who was responsible for maki, and one makicho, who was in charge of clerical work, were assigned to each farm, two bokushi per one hundred horses/cows were appointed to take care of them, and bokucho and his subordinates were subject to instruction and supervision of Kokushi (provincial governor).
律令制下においては、各牧には、牧の責任者の牧長（ぼくちょう）1名、文書事務にあたる牧帳（まきちょう）1名がおかれ、ウマウシ100頭ごとに牧子（ぼくし）二名で飼育にあたり、国司が牧長以下らを指揮・監督していた。