Iowa Code § 165.12: Tuberculosis-free herds.

The department shall establish rules for determining when a herd of cattle, tested and maintained under the provisions of this chapter, the laws of the United States, and the rules of the department and regulations of the United States department of agriculture, shall be considered as tuberculosis-free. When any herd meets such requirements, the owner shall be entitled to a certificate from the department of agriculture and land stewardship showing that the herd is a tuberculosis-free accredited herd. Such certificate shall be revoked whenever the herd no longer meets the necessary requirements for an accredited herd, but the herd may be reinstated as an accredited herd upon subsequent compliance with such requirements.