; (2) the administration of the medically important antimicrobial to the food-producing animal is necessary to prevent or reduce the risk of transmission of the disease or infection described in paragraph (1); (3) the medically important antimicrobial is administered to the food-producing animal for nonroutine disease control for the shortest duration possible to prevent or reduce the risk of transmission of the disease or infection described in paragraph (1) to the animal; and (4) the medically important antimicrobial is administered— (A) at a scale no greater than the barn, house, or pen level; and (B) to the fewest animals possible to prevent or reduce the risk of transmission of the disease or infection described in paragraph (1). (b) Definitions In this section: (1) The term food-producing animal means a food-producing animal intended for sale in interstate commerce. (2) The terms medically important antimicrobial and nonroutine disease control have the meanings given to such terms in section 512(q). . (c) Applicability The amendments made by this section apply beginning on the date that is 6 months after the date of the enactment of this Act.