Of course, any reaction in the short term would have been merely psychological. After all, the first shipped product isn't expected until early September. That means any Canadian product most likely won't appear until after the big demand of Labor Day.
Under the plan of the U.S. (followed three days later by Mexico), will still ban import of live cattle from Canada but will allow boneless meat cuts from cattle less than 30 months of age, as well as lambs and goats under 12 months.
Unquestionably, there remains significant concern about a glut of Canadian product. The pipeline for Canadian beef will clearly be full, but perhaps the situation won't be as bad as is being feared because the Canadians have moved a good portion of the glut through their own channels, albeit at disastrously low prices.
Other factors that might ease the border reopening are that the U.S. industry is extremely current and the number of cattle placed on feed the last several months has been understandably small. While nobody will argue that the border closing has been positive for U.S. producers, there's strong disagreement over the U.S. assuming the lead role in reopening the border to Canadian product.
That debate shapes up this way: Are the short-term price benefits of keeping the border closed longer than the science warrants worth the risk for long-term problems that might arise for U.S. producers by not making decisions based on the best science available?