There are a number of mechanisms. In the past CBSA has applied the risk management approach, as they currently do, and often it doesn't make the headlines. As you pointed out, supply-managed products are on the import control list, and therefore, are considered to be products that need to be monitored to ensure the effectiveness of our system. CBSA has conducted spot checks and found that some products were imported, the rules were not respected, or that certain goods were labelled differently than what they were. That led to very significant monetary penalties that, in certain cases, led to the closure of some enterprises. This has a certain deterrent effect. We have seen that the number of imports of spent fowl that has been declared as spent fowl has varied over time, and one could infer that it's because of these spot checks.
On April 16th, 2018. See this statement in context.