Imposes a moratorium on imports of Canadian beef from the 15th day after enactment of this Act until it is determined that such imports do not cause or threaten serious injury to U.S. beef industries. Requires the International Trade Commission (ITC) to determine, within six months of enactment of this Act, whether increased imports of Canadian beef are a substantial cause of serious injury or threat of serious injury to the U.S. beef industries. Ends the moratorium if the ITC finds that such imports are not a substantial cause of, or threat of, serious injury. Requires the ITC to update the study periodically if the ITC finds that serious injury has been caused or threatened. Terminates the moratorium, under such circumstances, when an update shows that the injury or threat of injury is no longer serious.