Mich. Comp. Laws § 600.6082

Sec. 6082. (1) Those persons committed on civil process shall be segregated from those committed on criminal process. (2) The board of any person committed under civil process, except for contempt or for collection of fines and penalties, shall be paid in advance by the judgment creditor to the sheriff or keeper of the jail. On failure to pay such board, the judgment debtor shall be released and shall no longer be liable to civil arrest on the judgment under which he was committed. (3) In the case of collection of fines or penalties, the board of the prisoner shall be added to the amount of such fines or penalties and collected as part of the original judgment.