The specified jockeys shall be weighed out for their respective mounts in each race by the clerk of the scales not less than 20 minutes before the time fixed for the race. In case of a substitution of riders after the original rider has been weighed out, the substitute rider shall be weighed out as promptly as possible and the name of the substitute and his weight publicly announced and posted.
N.J. Admin. Code § 13:70-9.36