There are all kinds of facts and figures available here: http://www.dairyinfo.gc.ca/

If Martha had bothered to look it up, she would see that there are actually 11,200 dairy farmers in Canada selling to three processors who then sell to three retailers. So you have a monopoly of farmers (who has their selling price dictated to them) selling to an oligopoly who then sells to another oligopoly.  If supply management goes, the two upper oligopolies will swallow the profits and the price will stay the same for consumers. The 1% get richer and all is well for Canada. Right?

The Globe & Mail has a very clear agenda against Supply Management, between Martha's guest articles and Barrie McKenna's monthly dairy article. Martha also doesn't mention in the article how much the restaurant lobby funds her.