With respect to each employee exempt from the overtime pay requirements of the Act pursuant to section 13(b)(13), the employer shall maintain and preserve records containing the information and data required by Sec. 516.2(a) except paragraphs (a) (6) and (9) and, in addition, for each workweek in which the employee is employed both in agriculture and in connection with livestock auction operations:
(a) The total number of hours worked by each such employee,
(b) The total number of hours in which the employee was employed in agriculture and the total number of hours employed in connection with livestock auction operations, and
(c) The total straight-time earnings for employment in livestock auction operations.