Oregon Revised Statutes Animals § 604.630

At the time a license is issued, the State Department of Agriculture and the licensee shall jointly make and record a physical inventory of all cattle in the feedlot of the licensee. Thereafter, such inventory record shall be maintained by the licensee and shall be subject to review or audit by the department at any time during the normal business hours of the licensee at least once a month for the purpose of reconciling the same with the records of the department.