Mandatory country-of-origin labeling (MCOOL) for some meat products went into effect on Saturday, Nov. 23 despite ongoing challenges from the US, Candian and Mexican meat industries. Consumer groups and some ranchers have supported MCOOL. The rule requires muscle cuts of beef, pork, chicken, lamb and goat to be labeled with information on where the animal was born, raised and slaughtered. Comminuted and processed meats are exempt.

Opponents of the rule say it could create unnecessary costs for meat processers, and worry that Mexico and Canada could respond with tariffs blocking US meat imports.