This article is a bit of propaganda at the very least. The US milk processors were selling processed milk products into Canada at below canadian prices. In a truly competitive manner our Milk Processors reduced their selling price to compete. They turned to the Canadian  Dairy Producers and said we have to reduce the price we are paying for your milk since we can not get the return we expected. Did the Milk Board or the Canadian Gov't get involved ? NO!
The US Gov't has an archaic  subsidy  system called price supports which forces farmers to over produce in order to get paid. The last figures show the US Federal  Gov't paid out $400 million to dairy farmers for milk excess to market needs. Thus it had to be processed and  dumped on the world market at what ever price it can get.
Canadian milk pricing is based upon the actual cost of production by the average dairy farmer. If you are below average in production efficiency you do not stay in business. Efficiency is a necessity