TL;DR Canada has highly protectionist dairy and poultry sectors that artificially constrict supply of dairy and poultry. You'll periodically read reports of dairy farmers intentionally dumping perfectly good milk [2] because they produced more than their allotted quota.
Even worse, all the federal political parties are too cowardly to stop it; in fact, the House of Commons recently passed [3] a private member's bill that essentially prevents the Minister of Foreign Affairs from negotiating any trade agreement that would weaken the supply management regime. (As you can imagine, Canada often gets called out for its hypocrisy during trade negotiations.) The politicians are scared to anger dairy farmers, particularly the ones in Quebec.
[1] https://en.wikipedia.org/wiki/Dairy_and_poultry_supply_manag...
[2] https://www.cbc.ca/news/business/dairy-covid-19-1.5528331
[3] https://www.theglobeandmail.com/gift/eca53705d5e7568f5ed88c7...