(1) All herds from multiple sources commingling in common pasture(s) that include male and female cattle shall have all nonvirgin bulls tested with the official T. foetus test conducted after the last breeding season prior to next season's turn out. This test is valid for the next year's breeding season unless bulls are commingled with female cattle.

(a) If any bull in the common grazing association is found to be a test-positive animal, all test-eligible bulls will be subject to the requirements set forth in ARM 32.3.502.

(b) Any stray test-eligible bull from an untested group that enters the grazing area of tested animals may be held under quarantine until the bull has one or more official T. foetus test(s) conducted.

(c) The expense of testing shall be the responsibility of the owner.

(2) Commingled grazing herds may be exempt from annual testing provided that a signed, written health plan including best management practices for all of the individual herds grazing in common exists. This health plan must be approved and signed by both a deputy state veterinarian and the state veterinarian.